Degenerative Disc Disease, which for normal people wouldn't fully effect you until you are older.. For me the surgery was at 27... it was sped up due to the work I was doing at the time..
I was an IT Field Service rep fixing and delivering Computers, Printers and those old 20"+ CRT Monitors.
You try lifting one of those old CRT's out of a trunk or back seat of a car without lifting "incorrectly"..
Since the final breaking point happened at work I was lucky enough to get all of the surgery( 12 hour surgery + 2 weeks in the hospital), plus some "pain and suffering" payment.
Some people miss drinking, others smoking.. I miss Golf