I never really thought of that, but you're right. I have two hybrids I created. One is from two strains of "pure" sativa the other from a cross of Swazi, Black Congolese and Puna Butter. The former is WAY up there with THC and the latter is the same except for it being very high in CBN's and is so narcotizing even a couple small bong hits and driving cars, following the plots of a movies or anything else that requires thinking are damn near impossible.
"Puff, puff, pass the Peace Pipe..."