what extent does experimenting with tobacco/marijuana and/or illegal drugs put individuals and society at risk?

Stimulants speed up the central nervous system.

This is first hand knowledge, top-level athletes, successful business people and achievers in all fields all  set goals. setting  goals  gives you long-term vision and short-term motivation . it focuses your acquisition of knowledge, and you to organize your time and your resources so that you can make the very most of your life.