What are things you've said AND/OR posted online that you regret doing so afterward?
For example, I regret posting this a year and a half ago on this site: I didn't say anything offensive, but I should not have said I "can't get into" musical theater; when in fact, as I've found out a little more than a year and a half later, I actually love a lot of it:
http://atrl.net/forums/showthread.php?t=316005.
I sounded ignorant & dismissive of something that people are really passionate about. I refused to open up to another form of entertainment. I had done it prior in my life, but because of high school & assumptions I made regarding it, I shut myself off to it & told myself that I wasn't going to like it. After growing up some more, I realize that there is so much beauty, creativity & talent to find in it, especially in the classics. I think it helps that I'm at a better place in my life than I was in late 2012, and the more positive prospect has opened me up to more things.
So I know this is a little excessive, but idk it felt right just to clear that that is not what I think anymore.
Also, as I said, I was pretty negative during 2011/2012 due to depression issues (high school is the pits), so it translated to everything: my thoughts on music, friends, grades. If I could re-do any period of my life it would be that one.
That's just my example.