up until the end of this summer, i smoked a lot of weed, I still smoke occasionally. but the short term memory loss is  signifigant, and if your tryng to do sciences (which i was) it really fucks you up. anyone who says blazing has no effect on their skills, try smoking and trying to do calculus the next day.
oh and if your not smoking, not vaporizing, brownies, etc..., weed is worse tfior your lungs than ciggarettes
that said, if you smoke say a coupole times a  month, you will basically be fine