I didn't get started til after I was out of High School. I was always fairly skinny at 6'1" averaging 165lbs. I started working out while overseas with the military back in '05. Once I got started seeing results and progression I was hooked. Of course everyone else noticed as well which was a bonus motivator.
Why I love bodybuilding/working out? Wow there are so many reasons. Really it becomes an addiction. I remember when I was younger and you walk into a gym having no idea what to do. All the equipment and bigger guys in there can be intimidating. Breaking that initial start barrier is the hardest. Once you get going though it's absolutely amazing. The feeling of pushing all that weight around. Seeing your body adapt to the weight and changing. Reading everything I can get my hands on to learn more and more. Being able to look in the mirror, identifying what I want to improve, and then knowing exactly how to do it is my favorite. Why do I love it? Because I feel like crap when I don't. I of course enjoy the attention it brings. I love motivating others to do the same. It's a hobby really!