+1 rep for real.
Are you talking about high on dope, weed, benzos what? The only one I can see that would be detrimental would be benzos.. but you mention nodding.
There are plenty of us here who got high all day every day and graduated college with flying colors. You mention nodding so I am guessing you mean dope. I don't know about anyone else, but dope does not affect my memory. I would MUCH rather sit in class high on dope than sober...much-less sick as a dog. If nodding and falling out of your chair is that much of an issue do a little less?
I did better in school when I was on dope.. I was more talkative, took better notes, was more alert etc..
But yeah I guess if it was the 1st time you ever did heroin and you are injecting it you might be a bit too fucked up for class lol.