I remember at one point when I was younger and newer to computers I was typing a document for school and being driven nuts by the damn insert key. Like I had zero clue as to why everything I was typing was just being overwritten every time I needed to go back and change something. I still think the insert key is absolutey evil!
I had a similar experience, but after I eventually figured it out, I grew to appreciate the insert key. Mostly because there were a few times when someone else was getting frustrated with the same problem and I was able to help them. It made me feel powerful; I had suffered, but I now possessed the knowledge to save others from the same fate.
Some legacy scheduling software I use at work, where ctrl+ins inserts the copied day for a given coworker. Useful if you need to swap days in the schedule and a coworker has 3 different classes in as many rooms, and in some classes there are students from multiple courses. It's archaic, but it saves time.
What shell is that? Bash and sh use Emacs bindings, C-y. Or if you meant terminal, urxvt and I'm pretty sure xterm use C-M-v. Maybe that's the gnome terminal?