Sure, but punishments generally take into consideration what the crime means overall. For example if you sold cocaine to a friend once in your life then all log

Sure, but punishments generally take into consideration what the crime means overall. For example if you sold cocaine to a friend once in your life then all logic says there's no need to prosecute you as a dealer (not that it wouldn't necessarily happen anyway), but if you were caught that one time the logic behind a serious punishment is the assumption that you're doing it more than once and thus affecting society. So even though they can't charge you with any more, the crime "selling cocaine" takes that into account with its sentencing already.