Bad parenting being overcome by maturity and good role models. I was raised very poorly by both of my parents, and picked up all of their bad habits. My dad smoked and drank excessively, was habitually late to everything, and would procrastinate things until the very last minute. My mom was obese, and overfed me basically from birth, despite my dad's protests (the only thing he did right in raising me, other than teaching me outdoorsy stuff like camping, hunting, etc.). By the time I was 16 I was a lazy, overweight, high school dropout pothead that couldn't hold a job for more than 2 months. My parents kicked me out of their house when I was 17 and I moved in with my older brother (he's 17 years older than me, I was the baby of the family). Over two years, he corrected most of the shitty things my parents taught me and I was a halfway decent human being. Joining the Army fixed the rest of it. I still have issues with overeating sometimes, but now I have the willpower to restrict my diet and increase my exercise whenever I notice I'm getting fat.