Well... i think 2 weeks is enough to reset your tolerance... for me, some 4 or 5 days without smoking are enough. After it, i get HIGHH when i smoke again. But, if i keep smoking daily after the break, the tolerance increases very fast, and soon it is almost as high as it was before taking the break.

And i also used to think that i would never get that highness of the first high ever again... but i did! I did read that 5-HTP (a dietary supplement) could intensify the cannabis high, so i took 75mg of it about 1.5 hours before smoking. Then i did smoke and... damn!!! I got the same feeling i got the first time i smoked. I even felt scared, much like the first time i smoked... it was amazing!
(Unfortunately, it seems the body also builds a tolerance to this 5-HTP very fast, so i only use it in "special ocasions", like once in a week or less, to ensure it works every time.)

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"Everything we do, everything we are, rests on our personal power. If we have enough of it, one word uttered to us might be sufficient to change the course of our lives. But if we don't have enough personal power, the most magnificent piece of wisdom can be revealed to us and that revelation won't make a damn bit of difference." Don Juan Matus - Tales of Power