My wife and I had a very similar discussion recently. Up until about a year or two ago, the college years were the best years of my life and I would have gone back in a heartbeat. I was in shape, damn good looking, had a lot of friends, beer was cheap, etc. No kids/wife/etc to worry about, just go to school when I felt like it, go to work, then go out to the bars every night.
I have 2 kids, a 3 yr old and a 5 yr old and have been married for 8 years. I've come to realize that I'm now experiencing the best years of my life and couldn't bear to not see my kids regularly and would miss my wife.