If you always did everything right, you might never know when you’ve done something wrong.
Cliche? Sure. But it’s also true. Sometimes a mistake leaves a little annoying reminder inside of you: “Hey, psst, remember the time you did that thing? Remember how you felt afterwards? Yeah, this thing you’re about to do? It’s just like that time. Do you REALLY want to go through that again?”
and so it becomes one of the bits of your conscience and helps you make decisions throughout your life.
Personal evolution. This stuff is a part of it. It’s like Pokemon evolving except you get many more evolutions. I’ve probably had dozens of evolutions – old “me’s” that I look back on and go, “Oh yeah, I remember when I thought that was a good idea but I’ve improved now”.