It's hard for me to pick something to do over again, since soooo many things had to happen in just the right way for me to have met my wife (praise God).
I'd say I wouldn't have gone to a "Christian" university especially the three years and massive monies I wasted at the university will haunt me for years to come, but being there put me in just the right physical location for my wife to find my profile on the dating site we both used.
I'd say I wouldn't have lost my virginity before marriage, but the relationship my wife and I initially shared was built around both of us just wanting to get laid.
About the only thing I can say for certain I would do differently, is not make a "hit list" to impress a rather homely girl my junior year of high school.
Made spending $400 on choir camp a waste, got me 30 days of "alternative education" (basically where they stick the gang members, drug dealers, etc.) AND got me 60 days probation and 40 hours of community service.
What makes it even more stupid is that within an HOUR of showing the girl the list (which in my nerdity I used my TI-83 calculator to write), I had COMPLETELY FORGOTTEN ABOUT IT.
When our "resource officer" (read, on-campus police officer) came to my next class to fetch me to the office (because apparently they thought I was dangerous, even though I had no criminal record and a clean disciplinary record up until then), I thought the principal just wanted to chat, she being a friend of my parents in our small town.
So yeah...aside from the "alternative education" staff reeeeally liking me (I was a straight-A student who had been taught to respect my elders...plus I got them pizza on my last day there), about the only thing I gained from the whole affair was a six-pack which faded within a week (due to the extreme workout routine they give delinquents...because the bullies aren't strong enough as it is).