We know Carlos dropped acid in the 1960's, which is likely where some of his most beautiful music came from.
Or maybe Carlos was experimenting with Datura, also known as Jimsonweed, Devil's Trumpet, and Moonflower. Shamans have been taking Datura for centuries. I'm not advocating anyone take Datura. LSD, yes. Datura, no. Datura sounds scary as hell, if taken incorrectly or in too large a dose. Ain't Mother Nature a hoot?
(some odd images here, but a helluva tune)