Well, the first of many altered ride experiences at the happiest place on earth
was my first time ever riding Space Mountain in 1978, just after smoking a joint with friends in the parking lot. (Come to think of it, the parallels with my first ever riding EuroDisney Space Mountain in 2003 after downing a bottle of champagne with a friend are striking).
Anyway, even though I had no sober reference point for the experience of hurtling through the blackness of space with floating chocolate chip cookies and psychenautic echo sounds, I knew instantly that the altered state put me a little bit more into the suspension of disbelief mode that befits the Disneyland attractions, and it was beyond effortless to accept Walt's invitation to play. Also, details were clearer, audio was more crisp, visuals were more colorful, movement was more keenly felt.
I knew from that moment that an altered state of consciousness was the perfect partner for experiencing playtheme physical environment creation attractions, and went on to get high on every Disneyland ride on every drug imaginable over the subsequent years.
I don't do that much anymore. I can still have plenty of fun at Disneyland without being high, and do so consistently. But there's nothing quite like Pirates of the Caribbean on ecstacy for appreciating the visual splendor, or hitting some dope in the smoking area just outside the Mansion to have a slightly creepier ride. And nothing in the world beats taking acid and then riding Space Mountain wearing rainbow-streak glasses and hitting on a nitrous oxide balloon as you're going up the last lift ....
Bonus Reply: Dunno. It's concept artwork from 'The Incredibles.' It's so delicious an image, but I don't know who the artist is. It's from an 'Art of' book that I gave to Isaac for Xmas. Yummy, isn't it?