Question: 20 years old should know?
Answer: 1) 'Who your friends are' matters. This is the most important thing. ... 
2) You're never too young. I can't stress this enough. ... 
3) Find your edge. I think it's really valuable for you to find your edge. ... 
4) Have goals. ... 
5) Stay fit. ... 
6) Time & speed. ... 
7) Get enough sleep. ... 
8) You don't need anyone's approval.