so in my science class, my teacher said if you smoke weed, it'll stay in your fat molecules forever, but it can eventually come out of hair grease that your body produces.

 So would weed molecules or whatever , stay in the body in the fat cells forever or will it be able toleave your body though gettin' rid of fatty cells/molecules ?

The detectable agent in weed is known as delta-9 tetrahydrocannabinol or commonly referred to as THC. Effectively, it remains active in trace amounts in urine and blood for about a month I believe. Definitely not forever, however, secondary sediments such as ash and char from the inhalation of the cannibis smoke without a filter, that I believe may stay in your body longer. As for the duration, it depends on how much you smoke, chief.

 "Smoke weed everyday."

If cannabis does stick to your fat cells, you can always burn fat if you don't want it in your system. I think you're confusing cannabis w/ LSD though, since the common myth(?) about it is that acid sticks to your fat cells.

I don't know about that. Every other country in the world actually considers the modern day research of cannabis whereas the United States is still stuck in the 1920's/"Reefer Madness" about marijuana and its effects. It doesn't make sense that alcohol is legal and marijuana isn't. There aren't really any significant statistics about accidents or violent crime related to cannabis. My theory is that since we have such a capitalistic, money-driven society, the US doesn't want to legalize cannabis because it may cause a decrease in productivity within the workforce due to the lethargy that cannabis consumption causes. I believe in the decriminalization of cannabis, treat it like alcohol: legal, but illegal to be driving under the influence.