What surprised you most about your job?

I work in 911 dispatch, I already had a pretty dim view of humanity coming into it and being prepared for the unexpected is basically the job description, so not too much has truly surprised me, caught me momentarily off-guard, sure, but not really surprised
Probably my biggest surprise is how few calls I get about foreign objects stuck in various orifices. I definitely thought that would be a bigger thing, but I guess most people choose to suck it up (phrasing?) and drive themselves to the ER out of embarrassment.
Also, overall, little kids tend to be pretty great 911 callers. I don't particularly like kids in pretty much any other situation, so that was surprising to me, but kids listen to me, answer my questions, don't beat around the bush and just blurt things out, and overall tend to be respectful. There's outliers and exceptions of course, but overall some of my favorite callers are little kids.
- I've had to take someone to the ER after losing a toy in her. An ambulance ride seems like an unnecessary expense unless there's like broken in there.
  
  I work in X-ray. Get a foreign object like once every two weeks. Good times.
  
  Don't get me wrong, personally I'm not taking an ambulance unless I'm actively dying, or physically incapable of driving or getting into a car with help from whoever's around me
  But I've had people call for EMS because of stuff like a highish fever, nausea/vomiting, minor broken bones, strains, sprains, depression/anxiety or other fairly minor mental/emotional/psychological issues with no suicidal ideation or anything else presenting any immediate physical threat, food poisoning, head lice, and my personal favorite "just not feeling right" but unable to describe any actual symptoms.
  And that's not counting the people who don't want an ambulance and just want to ask what they should do or if I think they should go to the hospital (and the answer is pretty much always something like "if you're concerned about it, you should probably be seen by a doctor," I can't really treat or diagnose or give medical advice, what we give are "pre-arrival instructions" which are basically "here's how to avoid dying until the ambulance arrives, and then you're their problem") or just want the ambulance to come check them out and see what they think (and again, that's not really their role either, they have more medical training than I do but their job is basically to keep you alive until you get to the hospital)
  Couple personal favorite dumb medical calls are the guy who accidentally ate a pretty decent quantity of raw ground beef (his wife premade some cabbage rolls or stuffed peppers or something, put them in the fridge, and was going to cook them the next day, then he had a couple for a midnight snack) he wasn't feeling sick (at least not yet,) didn't want an ambulance, just kind of wanted me to tell him what to do, ended up connecting him with poison control who basically said (in much kinder words) "you're either going to get food poisoning and throw up for a couple days, or be perfectly fine, nothing you can really do either way, so suck it up." He then wanted to know if he could get prophylactic antibiotics.
  There was the little kid who got kool-aid in their eye
  The one who wanted an ambulance for head lice
  The person who was sitting on the toilet, saw a mouse run past, lost sight of it, and was absolutely certain that it crawled up their butt
  Now that I'm thinking of all my medical calls, another thing that surprised me a little, is just how clueless a lot of people apparently are about even very basic medical questions. I don't really expect people to have even basic first aid knowledge, but I get stuff like this every night
  "Are they conscious?" No "Who's that talking in the background?" That's them. Unconscious people don't talk.
  "Are they breathing normally?" I don't know. "Look at them, is their chest rising and falling?" Well they're laying on their side. Really?
  "What's not normal about their breathing?" I don't know "Are they breathing at all?" Yes "Ok, try to describe it to me" I don't know "Is it shallow? Is it heavy? Are they gasping? Coughing? Making weird noises? ..." I end up having to list just about everything that could possibly be wrong with someone's breathing to figure out what's going on

Just how fucking garbage it is. Working for a non profit that can't decide on what they want, refuse to let me create an app that's actually useful, and just want me to spend days customizing a low code platform through hacks. Then they complain when things take time. I really need a new job.

That a multi-national medical device company has no spare parts program for it's machines, and uses Excel sheets exclusively for performance tracking.

How much old tech they actually have... like rooms of it... most of it is kept for spare parts.
- I used to work IT for a medical research office. The amount of time I spent on ebay finding compatible replacement parts was insane. So much equipment just was never updated to work with new hardware and OSes. I wish we had a stockpile lol
  
  Actually, these guys keep EVERYTHING. Like litelarly everything. It's a TV station, so basically there is no need for the old equipment to be hooked up to PCs, cuz it's just used to digitalize old tapes, but still, these things are huge, so you need a shitload of storage. Luckily, they have it, so it's not a problem.
  I sometimes feel like treasure hunting when looking for parts, lol. I'm the IT guy there, but if it's a small fix, I sometimes do the tape players as well. Head change and stuff like that, not really a problem. Anything bigger, let's see what we got in the pile... well, waddaya know, here is one that works, here ya go 😁.

That my coworker gets paid more than me for just sitting on his ass looking at his phone all day while I do all the work and they don't seem to give a shit.

Honestly, the most surprising thing is that most people hate it. I'm an accountant because I love numbers and organization, but didn't want to go into engineering. Every company I've worked for has an accounting department of very sad people. They talk about how they wasted their lives going into this career, "but at least it's a stable paycheck, y'know?".
The pay! I had a few different careers I was considering, but went with accounting because at the time it was one of the only careers with legitimate online degrees. I've been in the field 4 years now and make $100k. That puts me at the top 5% of household incomes where I live.
The lack of actual work. I'm here for opening the books at the beginning of the month, closing at the end, and not much else. 75% of my days are a whole lotta nothing. At my current job we bring in video games on Fridays and play at the office.
- Older me kinda wishes younger me had considered accounting, but younger me was hung up on your first point. Younger me didn't want a boring job. Older me is like "I don't have to love my job, I just have to not hate it. I can do the things I love during my time." And a low key, low stress, high autonomy job kinda nails that. I'm kind of accounting adjacent (data analyst) and it's working out so far, but there's probably more salary stability in your career vs mine. The February to May crunch kinda scares me tho.

How much time I spend not actually doing any work. I'm in IT as a computer technician and I work public sector.
A lot of the time, I'm kinda just sitting at my desk wasting time. If things aren't broken and no projects currently need me to work on them, then yeah. Not much to do but wait for something to break.
- Firefighters do basically the same thing
  
  I often describe large chunks of my job as "Fire duty". If I've done the initial bit right, I've got nothing to do for a large chunk. If I'm running around looking busy, it likely means I've screwed up somehow.
  Where's the best place for a fireman (fire person?)? It's not out putting out fires. It's sat, bored, in the fire station because there's nothing left to do, and no fires to put out.
  
  And just like firefighters, IT needs to be in continuous training. Are you able to execute in an emergency? What do you need to know that's new? Lithium battery fires or new malware vecors.

How incredibly stupid the customers are.
I guess anybody who works in any sort of customer service gets this, but I swear to god, 90% of our customers can't even fucking read - which is really bad when you work for an online retailer and most of your interactions with them are through email.

Just how little it seems people in my role seem to actually do or know about their role.
Also how it seems that every time I try to make requests based on facts, figures and numbers it always ends up being more of a we'll do things based on the vibe because they don't need to see the data as they already " know " the data.
Basically, I make a request for more budget, but I get pushed back your budget should be like Y budget as we have looked at the numbers and deem it so. I have data that proves our budget can't be like Y budget due to 2 to 3x the workload. Surprised Pikachu face.
It's happened to me 3-4 times now and it makes me think maybe I take my job too seriously.

When they found out that a contractor was using prison slave labor after looking into a significant number of defects, they were cool with it, business as usual.

How much time it takes to fill reimbursement forms. And how few professors/researchers discuss about teaching. (you got it, I work at a university).

I work retail and honestly?
Just how clueless a lot of managers are when it comes to how the business works in general. These are the people responsible for that exact thing, and they just seem to be so out of touch with how it works.

That people (both the CTO and devs) eventually asking ME for suggestions. And acting on it even if on projects I've barely touched while working there. They been through multiple years of university and some have been through multiple jobs. I'm just a guy who knew a bit programming when I was hired as phone support 13 years ago.
I love the team though. It was just me and the CTO that did dev for many years, and now we are 7.
- Something I heard a while back. A leader, when getting advice, should be the dumbest person in the room. Not because they are dumb, but because the surround themselves with people even more intelligent then themselves.
  By the sound of it, your working with people confident in their own skillset. They also know when an outside voice might have a useful perspective. You also likely have a significantly different experience base to them. To you, something it obvious, to them, it's really not.
  I once saw a project (7 figure) that was being used regularly outside. It's only when the field techs got to play with it, one asked how waterproof it was? It wasn't; at all. The head engineer was so laser focused on the technical, he missed the woods for the trees.
  
  You can still be the smartest person in the room, and play the dumbest. Ask questions, you might find new data points you needed to make a sounder decision.

How toxic corporate environment is.
I had only worked for small businesses before. Obviously they had a lot of problems and I don't miss a single thing. But now I'm in a huge IT company that outsourced part of its operation to the another huge IT company I'm actually in.
Both suck, but still I gotta learn to "play the game".