The biggest problem with eating pot brownies before the concert was it required planning. Since it took about 45 minutes for the brownies to kick in, you wanted to leave yourself time to get there, because if they kicked in while you were driving, you might never find the venue, and you'd end up driving aimlessly around town with your friends, listening to Ummagumma on the 8-track, eating Fritos and drinking Bubble-Up. So you wanted to get there before you were completely stoned. HOWEVER...you wanted to be stoned when you walked into the concert, so ideally you'd smoke a doobie in the parking lot to bridge the gap.
This sort of stonership required a high degree of organization, and most of all the ability to "maintain", which I never had. You would usually have one guy or girl who had this innate ability to maintain, allowing the rest of the crew to be nearly completely incapacitated. This person was the driver, and could be counted on to speak with the cop if you got pulled over for the broken taillight on your VW bus. This person is now a retired stockbroker, very likely.
I agree, drugs are not funny, with the exception of pot. Pot is hilarious.