Go Back In Time

Ok, so, after seeing the many previews for the upcoming comedy "Hot Tub Time Machine" (which has me cracking up) I began to consider if I could go back in time and change something, would I and what?

I must admit, I wouldn't. Things may not be where I want them to be in my life but they are where they should be. I am one of those "everything happens for a reason" believers. Although I would love to be further in my career, things are happening as they should.

So I ask you, if you could go back in time and change something about you life would you and what?