I was just at the start of being overweight in high school. I didn't really care about what I looked like. Then I got my first job, which required some physical activity, and I ended up losing some weight. Cut out soda, lost more weight. At some point I noticed that my abs had become visible. Thought it was pretty neat, so I started doing situps every day to work on them a bit, and eventually got into pushups as well since seeing muscle definition develop was pretty exciting. Stated counting calories and lost more weight.

Since then I've kept the weight off, built up a nice workout routine and a pretty good amount of lean muscle, and I'd say having defined abs is honestly my biggest source of self-confidence.