^ This is why, for better or for worse, I'm often willing to give the benefit of the doubt to someone who's absolutely convinced they've had an otherworldly experience of some kind, and have learned from it. So long as what they've experienced has not motivated them to hurt or alienate other people, I'll not be the one to raise an eyebrow and pull out my DSM-IV. (No, in case you're wondering, I have no interest in specializing in psychiatry.)
Because you really never know. If Chuang Tzu woke up and realized he was a butterfly, and proceeded to tell all his butterfly friends about his other life as a human, they'd surely put him where they put all the 'crazy' butterflies, and he'd be glad to find ONE who'd take him seriously, even if being human was only a dream.
One of my most profound drug experiences (k hole) has forced me, perhaps for the rest of my life, to take very seriously the possibility that I am living in a simulation, or that the reality I see every day is but a veneer. I'm still grounded in reality, in that I follow its rules. (You'll never find me pounding on a plate glass window screaming to let me out of the Matrix.) But I'm more willing to entertain the idea that surface reality hides a lot, and more willing to entertain those who are certain they've seen beyond.