U R Special. In that Short Bus kinda' way. It's sad, in a way, at the same time, I like to laugh at people, so I'm conflicted about responding and educating you.
Oh hell, here you go. They test for what are call "metabolites" see, THC is a canabinoid that is utilized by the CB receptors (CB1 and CB2, in the Brain and Central and Sympathetic nervous systems, for those taking notes.) THC is indeed rapidly absorbed, used, and processed. But, the trick is, as it breaks down, it breaks down into those "metabolites." Now, in your blood, you are actually pretty good (cuz, your liver passes waste into your kidneys, not your blood -- you lucky bastard!) Your hair, yeah, you are fucked, especially if you wear it "traditionally." Your piss? Well, that's where the waste comes out, so fucked again, until the metabolic half-life "expires" on all of your waste, and your body passes it out. In conclusion. Dude, don't look for your bong, look for your biology and chemistry books. (And, I expect I'll be corrected by our Almighty Polar Bear, where I mistyped -- for which, I'm blaming the Guinness.)
