I got accepted to, and graduated from, the United States Military Academy at West Point. Since I'm elaborately lazy and loathe structured environments I graduated with a 2.7. Winning.
I kicked ass as an officer, because I didn't respect authority for authorities' sake - I was there to win, and to support my troops no matter what. In retrospect, what happened next was a good thing, as I wouldn't have made it in the political environment officers need to thrive in later on.
As a young officer I was training for a special forces role and ranger school by snowshoeing in -40 (near Granite Tors, Alaska). Got lost by following a dumb moose and ended up with 5th degree frostbite. Ended up losing some digits and getting retired out of the Army. Fail.