To "get high" off of something means to feel especially good after doing something. That something might be algebra, some kind of drug, or perhaps a really good book. The high off of illegal drugs, though, is synthetic and is NOT a good high, as it brings your mood straight down after you get this high.
You might laugh at the slightest thing or feel free of worry. It depends on the individual, really.
Person 1: "Yo, do you want to get high off this new thing."
Person 2: "No, I'm not crazy like that. I get high off of good things that don't bring me down. Here's an awesome book." -hands person 1 a book-
December 31, 2005