I seem to have a fairly low tolerance for most mind-altering substances, except John Denver records and Hostess Cakes. That's probably been a good thing, because otherwise I'm sure I'd be eating sandwiches of LSD all day long.
While I've never been a huge fan of Dr. Timothy Leary, I do have one favorite quote from him that goes: "advanced age is like an altered state of consciousness". I think that's about the most positive spin on aging I've ever heard, which leaves me with that to look forward to.
Meanwhile, I've been reading about alternative attitudes on drugs, without actually taking any. LA tap water is mind bending enough.
I've also been watching a very interesting hippie chick on YouTube. She's got a mess o' videos about her experience with almost every conceivable "Entheogenic" drug, laying it out in the most wispy "everything's good and everything's OK"-kinda' way. [Some things are not good: Namely, I do feel bad for the toad in the video.]