I don't drive, drink, do drugs or anything
There is no age requirement for any of these things. Lots of people do these before they are 18 and face the consequences (or lack there of if they are lucky).
When I turned 18 the first thing I did was legally purchase a pack of cigarettes. 10 years later I don't feel any different about to turn 29 than I did when I turned 16, 18, etc. Age is all how you feel and how you use the wisdom and experience you've gained.