My mom is a nurse, so my sister and I were quick to learn plenty of healthy habits as kids. Even as a toddler, I was tricked into thinking that corn flakes were potato chips, yogurt was ice cream, and wheat germ was "special sugar." Bread only came in whole-wheat, and sugary cereal was for dessert, not breakfast. It wasn't until I started school and learned about white bread, E.L. Fudge cookies, and Thousand Island dressing. When I was old enough, my mom sat me down and explained why she chose the foods she did, and why she restricted others. Not only did it make sense to me, but I actually preferred the healthy foods she chose.
As I got older (excepting a rebellious phase at age 10 and then once again in college) that was the lesson that stuck with me the longest; I still hear my mom's voice in my head when I'm picking things up at the grocery store. I can't stand white bread, and I still love the taste of wheat germ.
Have you picked up any similar strong habits from your parents?