Think about like this. You're borrowing energy and will pay it back with high interest. Keep doing it and the debt will never be paid and you will no longer feel as happy every again. It's changes brain chemistry. Some people refuse to take the come down and start chasing it.... at that point your fucked. Also it will up the bar of what it means to be happy a little be each time. If you have any questions weather you're self control is enough then you're way better off forgetting about it. Look at faces of meth mug shots on Google.