Actually, I know one thing I would have done differently. Slightly long story.
My parents used to have some friends who had two kids. One was a girl of about my age, the other was a boy with down syndrome. The latter one always got way more attention than she did, in a really, really awkward kind of way, but with the best of intentions.
Back then, my dad had his own kitchen company, where their dad worked as well. At some point, their dad became depressed and got a burnout. After some hassle over a company car, the friendship just watered down and ended. I was 16 at that point, it's about 12 years ago now.
I'm talking about two families that used to go on vacation together, that visited eachother weekly for over 30 years. I grew up with that girl, and when I was still too young to understand what it meant, I always thought I would grow up to marry the girl. That's how close we were before the rough split.
I didn't speak to her for years, only to meet up with her (found her through the internet on some profile page) about a year ago. We talked about those times, the good and the bad, and how things had went bananas. It was very awkward because obviously both sides had suffered "damage" from the breakup. It was then though, that I learned how bad she had suffered.
Her dad had slipped further and further into depression, until at some point, she had come home to find her father in the kitchen, having taken a knife to his wrist.
He lives, but obviously, that must've been a truely horrible event to experience.
So, if I would know then what I knew now, I'd have done a lot of things to fix all of this, and at the very least, I'd have been there for her.
This is the first time I talk about this. My parents don't even know this. Heh.