Legal age !!!!

What i dont get in this place is legal age ? ? ? ...like really 99.9% of the people in the world dont follow taht rule and thats a FACT..i think that its a good thing but thats putting kids under pressue to wanna drink. smoke. etc...beacuse they see everyone else doing the things they have to wait to do..makes them hide and do it( some do it to look cool) * ( some do it beacuse of friends) * ( and some do it beacuse of special reasons ) * but i personally believe that they should do as they feel beacuse this is a freedom country. but then on the other hand they should wait till they get older to do the things that they wanna do.