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.)