If we knew then what we know now...

It's natural to look back on the things you did while growing up and wonder what might have happened had you taken a different attitude toward something or someone.

Call it hindsight or hubris, (the good kind you have as a kid when you feel invincible) we'd all like to replay a few scenes. 

What are some things you might have done differently after graduating? And, if you haven't graduated yet, what are some mistakes you've heard others make that you're not going to make?