alright i did read what you posted, and it says...

"There is almost no Delta-9-THC left over a few hours after smoking marijuana"

and even before that it says that Delta-9-THC is what gets you high..

so if thats true, that there is almost none left in our bodies a few hours later, then how do we build a tolerance to it? If there isn't any left in us shouldn't we be able to get just as stoned the next day, and the next, and the next...