Definitely grammar is a main one. Maturity is also another, you can't get into a good end-game guild without it. Learned how to thoroughly fill out apps. Examination of other people's playstyles to better yours, learn to not whine about not getting your share of phat loot, & most importantly don't start drama. 1337speak & Lrn2Skill.
All of this actually helped me in my life one way or another.
Plus I'm underweight thanks to not leaving my comp for anything.
