I think I have to possibly retract my previous skepticism in this thread.
Because I think I just felt my dantian for the first time, after doing this:
I do weird stuff like that (I guess I'd call it freestyle yoga?) because it just makes me feel good -- no superstitions about it and no particular emphasis on learning and memorizing particular forms.
Anyway, after doing that, after the ninth pose... In my stomach, for several seconds, I felt a strange sensation. Might've just been indigestion combined with a tired and over-imaginative mind, but I'll experiment with it later on. In the past, I just thought the dantian was people being really mindful of the fact that belly fat is such a big source of stored energy (that maybe with deep concentration you could actually be consciously aware of belly fat being catabolized).
Others describe it as cosmic energy, a "vortex," etc.. For me, it reminded me of a toilet flushing.
I was thinking a bit earlier today that my thoughts on chi might be a bit mistaken. As lately, I often do feel this kind of tingly energy in my body. When I'm really energetic, it feels like a really minty vapor in my nostrils. When I say "energetic," I mean the energy that overcomes laziness, like when my body and mind tells me to sleep, but I refuse, and it's like I have to drag around a tired and lazy corpse. And when I meditate or concentrate throughout the day, of course, I'm often feeling various spots in my skull tingle.
Still think a lot of Chinese alchemy, etc., is nonsense, though. Lots of foolishly materialistic interpretations of mind medicine that result in emperors getting cinnabar poisoning.
The best things in life aren't things.