I have always wondered if it was variations in contaminants or real differences in the formulation of the LSD that made for differences in the trips one would experience (so I am told, wink, wink) when they dropped. There was the the mellow buzz with soft edges of the blue cornered sugar cube (LSD 25), the wild colors and and zippiness of the violet sugar tablet (Purple Haze), the rowdy feelings of invincibility in Orange Barrel, and the serenity and peaceful blur of Baby Blue Windowpane (which has prevented me from ever watching the movie American Graffiti).
A good chemist is hard to find. Back in the 60s-70s we never knew what all was in it, and I bet we wouldn’t have balked had we known. I just know that the speedy stuff was tiresome.
I never got that, myself. Generally speaking, LSD is cheap enough that cutting it with something else doesn’t make much sense. Had to give it up half a life ago because the last five times I tried it was bunk (and speedy!) Good thing the mushrooms never disappoint. Shame I haven’t seen any this decade.
(Unlike most Americans, at least I know my nostalgia is based on hallucinations.)