This is a false belief. If could only take one time to become addicted. Or that one time could be the time that something very serious happens to your health. Those aren't the kind of odds one would want to be on for a little fun over Spring Break. Marijuana is the most commonly used illegal drug.
Many people prefer it because of the feeling of euphoria and relaxationt that it provides.
With that relaxation however, one's mental state can be altered to the point of being incapable of driving a car safely. There is also an altered sense of time and short-term memory can be affected. Lung damage can also result from marijuana use. Amphetamines or stimulants are also very dangerous. Some examples are ecstacy, uppers and speed.