When I was in college(Auto-Tech), I did a semester at school and then a semester at work with a mentor learning hands on.
My mentor was a monster(To me anyways), he was 6'2", 300lbs +/- at the time. He busted my balls ever day telling me I needed to start training. I was a young punk stoner at the time, 5'5", 120lbs soaking wet with skinny arms and a pot belly. Underdeveloped is an understatement, lol. I didn't have any drive to do it, and kept brushing it off. At the time, I'd rather get baked with my friends after work than hit the gym.
After a year or so, I was hanging out with some friends and some girls on a Sunday night. I was determined to hook up with one of them, and all of the sudden during conversation, she told me I was skinny. Looking back, I had no clue I was skinny, I obviously new I wasn't "big", but skinny? Never even crossed my mind.
That shit fucked me all up. I didn't get laid, and couldn't stop thinking about it. Skinny? Really? WTF?
I went into work the next day, and told him I'd come train at the gym after work. Little did I know, I was fucked! First day, LEGS! I had lifted weights before, but just fucking around on a bench or doing curls. The next 3 days I was so fucking sore, I had to call in sick to work, lol. Couldn't even walk. Pretty sure he was trying to break me, but I'll never quit, it's just not an option.
Once I could walk again, I was back in the gym for more punishment.
Years later, I saw that girl again. She barely recognized me. I thanked her, because she changed my life. Still didn't hook up with her though, she was married had some kids by then.