0 Things to Learn or Be Taught by Age 20

Sources to summarize
What a Man Should Know
7 Skills You Need to Learn 
10 Life Lessons People Need to Learn before Their 30 
10 Highly Desired Skills You Can Teach Yourself 

Basic First Aid
Auto Maintenancne
Right or Wrong
Know any substance entering the body may be harmful
Risk and Reward ... Risk vs Gain 
Get Respect when You Show Respect
Money Management and Investing (budget, risk/reward, living beneath one's means)