Would the phrase "live like you're going to die young/soon" be better as, atleast for me, it means that you should live life to it's fullest and try not to waste time on meaningless things
If you live thinking this you're only focusing on stuff which, at your point in time, find meaningless. Finding meaning in things changes drastically over time, and your point of reference is based on what you believe at a certain moment. During your childhood you probably found playing with toys to be "meaningful", but now during your adulthood (assuming you're an adult lol) you look at playing with a firetruck to be meaningless.
See the difference?
The time wasted on meaningless tasks are usually memories and experiences which we hold very dearly to. I'm sure as you get older you will regret not doing a certain thing because you're too worried about the future, and how different actions will cause different results if you waste a little time. I know for a fact that I already regret not doing the "meaningless" things I thought were a waste of time, like spending more time with my now deceased dog. I took for granted that he was alive, and never really spent nearly as much time as I wish I did, thinking that an hour of work was more important.
Contrary to what I've been saying though, the manner of living life like "you're going to die young" is also pretty valuable. You don't want to be on the extreme that you simply don't care about the future, and try to attach meaning to every action you take - it's destructive.
Really, there's no "right" way to live life, you can only live, make mistakes, take insight from your mistakes and mistakes from others, and to create your own way of living. It does sound corny as hell, I wont even lie, but think about it and do what you want with the knowledge you have right now.
I'd like to add that even scrolling social media like Reddit, Facebook, Lemmy etc can be meaningful. I find it's like walking around town looking at what other people are doing. Listening in on someone ranting from their soap box, participating in some open air discussion, looking at cute cats in the park and learning something from a mechanic talking through a problem with someone standing beside a broken down car. It's also a social experience even though it can't be your only social exposure it still provides something.
It really is about variation and moderation. It wouldn't be meaningful, in my opinion, to spend your life on a rotation of the gym, cooking healthy, reading about those topics, working hard at some nameless corp and sleeping properly. But if you don't normally go to the gym it's suddenly meaningful to go. Life is about experiences and about challenging ourselves to find out who to be and how to be the subjective "best" version of ourselves, and that quest has no truly meaningless activities, all roads lead to the end of life and while we might regret some activities that regret in and off itself is a lesson that we took with us.
Thank you for this, I think it's now more about trying to become fulfilled in whatever position you are in life and trying to make the best out of our lives.
Although, as you said, there isn't a right way to live, but I personally think that we should strive for improving what we can, with the little power over the world we are given and to avoid hurting and making other people's lives worse.
I already regret not doing the "meaningless" things I thought were a waste of time, like spending more time with my now deceased dog. I took for granted that he was alive, and never really spent nearly as much time as I wish I did, thinking that an hour of work was more important.
The thing is, I don't think spending time with loved ones (your dog for example) is meaningless, infact I think it's very meaningful.
I was not saying that spending time with my dog was meaningless, just that I prioritized my work, indirectly issuing "less" meaning to the time I spent with him. Either way, the past is the past, I can only go up from here.
Tbh I'm not sure lol. Personally I've struggled with a lot of mental health issues since I was young so I'm finding it hard to say whether we should live life to its fullest or just accept the feeling of finally feeling ok. What do you consider meaningless btw?
Since reading some other comments, I don't know what is meaningless anymore, I now think that you could find meaning in everything if you looked.
I think rephrasing the original would do better, it should probably be about living a fulfilling life without harming others and not ignoring good opportunities because you think you should wait until the perfect time that'll never come.
However this ignores unavoidable pain that we all get in some way or another, in your case mental health, so I'm still not sure what would be a good way to live, as we aren't always in a decent enough position to take up the kind of opportunities I said earlier.