I did when I was young and I survived. It is true that all teens engage in some type of risk-taking behavior at one time or another. However, experimentation with substances during the teen years is just too risky. At this age, impulsiveness is high and judgement is poor, inviting the possibility of real physical and psychological harm. Substance abuse among teens occurs in a predictable pattern.
Kids begin by trying tobacco or alcohol, and if the situation is ripe, experiment with marijuana.
While it's certainly not inevitable that a teen who smokes or even drinks will progress to using marijuana or other drugs, once experimentation with substances has started, there's a greater chance that further abuse will happen. Think about the kinds of things teens must do to smoke at that age. They have to get someone older to buy the cigarettes, hide them at home, and then smoke secretly. This is the same pattern of secretiveness and lying that's necessary for other kinds of substance abuse. Different kids use substances and progress from one substance to another for different reasons.