It's been at least 4 months since SWIM tripped on acid, and she still remembers it with good memories.

It was her first time dropping acid with a good friend (who is experienced with drugs, but was also a first time with acid) and they researched about it beforehand (maybe not as much as they should have, but some knowledge is better than none IMO). The trip was fucking AWESOME! SWIM says it was the most mind blowing drug she's ever tried, and her friend agreed. It was everything they were expecting and so much more. It was a great day/night.
The next day SWIM felt a little sick and exhausted, but she took a multivitamin, drank a bunch of water and felt fine, if still a bit tired, definitely not as bad as she expected to feel. Her emotions on the other hand confused her. She didn't feel bad, actually the opposite. She was in this very calm, mellow mood. Nothing, whether it was good or bad, could change that mood. It was a nice feeling to be that way, but it was like she didn't or couldn't have any reactions to anything that was happening. Nothing upset her, nothing made her really excited. This lasted for about 2 or 3 days, then she was back to normal.
SWIM talked to the friend who tripped with her, and he said he felt the same way for a few days, too. He described it as being "in such a passive mood, it's been weird like almost nothing annoys me anymore." It wasn't a bad thing, just kind of odd.
Well my question is, has anybody else experienced these feelings after dropping acid? Or maybe something similar to it?