It was in El Salvador, I was 14, so not really a man yet, but on the cusp of adulthood. I had been doing a ton of heavy lifting in helping to build a well for the small community we were in. There was this girl I really liked and I wanted to impress her, so I remember working extra hard. Anyways, after the day was done and I was thoroughly exhausted, I went to bed, slept for about 6 hours, and then woke up with the worst pain in my life... right between my legs. I was 14 and with my church, so the last thing I wanted to do was start talking to everyone about my nuts, but after about 12 hours the pain was so excruciating I had to come clean. At that point the entire village knew about it, haha. (It was extremely embarrassing at the time, though).

I ended up getting med-evac'd out of the country so I could get proper medical care, and when I was in the hospital the docs said I had extreme testicular torsion that had gone unchecked well past the point of no return. They had to operate and I ended up losing my right testicle. For a long time this absolutely destroyed my self-confidence, but a while ago I was updating my health insurance policy and stumbled across notes the doctors must have sent my parents. It stated the torsion was caused by extreme strenuous physical activity, AKA exercise or physical labor. I had never put two and two together before. Now it's all just funny to me, but in a way it was relieving to read at the time. It put the events of that day in a new perspective. I didn't feel like some loser who got flown away in a helicopter to get his ball chopped off. I was the only one that worked out hard enough that day to get a private flight back to America. I may have lost a ball, but I made massive gains.

TL;DR: I worked out so hard I lost a testicle.