I could feel whent he weather was changing, and sprinting down sketchy mountain slopes because I understood how the physics and movement would work.
I think you've just explained to my whence comes my deep love of a series of fantasy novels that I've just read for the third time - Stephen Donaldson's Chronicles of Thomas Covenant. The characters are pulled into The Land, a fantasy land where health sense allows one character in particular (a doctor) to experience just what you've described above. It's never really made clear whether it's a delusion, but it's a heck of a lot of pages in that land!
I've experienced this kind of thing on psychadelics and other substances, but only ever had very brief glimpses in sobriety. It's that that I'm seeking I think.
12+ years in AA have taught me a lot about myself, fear in particular, and that's a thing I deal with every day.
Same, though it's getting better for me. I've been practicing meditation and that's been really helping get back to that flow-like state where there was just no fear for me.
I almost read those books when I was younger but couldn't get into them. Might've been too young for them.