That's right, that's how I had experienced it before, as extremely stimulating and making me awake. I didn't take a pill at the time, but it was in liquid form, I was told it was "pure MDMA liquid ecstasy". So I was surprised myself that it gave me a trip. Who knows what was in it.
I can confirm the overwhelming effect you describe and had actually only experienced it with shrooms. At the same time, I always had an irrepressible need to laugh at the beginning and only once did I cry for about two whole hours and retreat to a dark room where the party people visited me from time to time to check on me. I said everything that night that I would never say otherwise, for example because my girlfriend only said stupid things. LOL. Truth serum, but not of the evil kind, rather an inability to lie, but without spitefulness. Yes, the sense of time goes down the drain, eternity is not one :)
For a while I had considered taking part in an ayahuasca ceremony, but there was no real reason to do so, other than curiosity. Which I feel is insufficient, because it seems like it's a very earnest thing to do.
Those times are long over and today I have much more respect as my body wouldn't cope so well any more. Or so I guess. (Same with alcohol, drinking is not so much fun as it was).