When I was a Junior in High School, I blew out my ACL playing on the basketball team. I was devastated. I loved playing, and it kept me fairly lean and in shape. It took about 8 months to really rehab and get back to at least a functional status, and in that time, I unfortunately put on quite a bit of weight due to stagnancy and my metabolism slowing down.
My Senior year, I signed up for weightlifting class and it changed my life. I was up to almost 220, from the previous year of 170. I began lifting 5 days a week and slowly began turning flab in to muscle. By the end of the school year, I weighed 235, and showed enormous muscle gains.
Unfortunately, my routine and efforts faded when I got in to college and in the work force, but I have re-dedicated myself and am slowly crawling back and beyond where I previously was.
It's my canvas to put it poetically. I'm typically a fairly easy going person, but I tend to internalize stress, and it weighs me down. With bodybuilding/weightlifting, it gives me a constructive outlet. The more frustrated I am, the harder I push, the better I become. It's literally like a conductor for all my stress and negativity that transforms it in to a better me. Who doesn't want that?