I've always wondered that too, why the drinking age is so high compared with everything else?
Another thing I've found interesting, completely unrelated to the above, is the sheer number of commercial breaks when watching TV and the abundance of ads for pharmaceuticals - all of which seem to have a concerning amount of side effects listed. Obviously the world of healthcare is completely different in the US to what we have in the UK but I've always wondered how these commercials go down for locals.