Does anyone else notice the length of a moment changing? I especially notice a difference if something causes me to trigger an adrenaline rush; I noticed it a lot when playing DDR and similar, since the physical motion would trigger adrenaline, and then the tempo of whatever I was playing would appear to slow.
It was like ... to use a game developer's terms, like my perception was suddenly running at a higher framerate. Of course as a musician this meant the music felt "wrong" somehow after that. "Why is it so slow? Was this song always this easy?" and relatedly, "Why is it harder to move my legs quickly?" etc. This persisted for maybe 20 minutes and then returned to normal gradually. Once I pieced together the criteria, I started to notice that sort of tempo... kind of a "beat" in everything that I do. I feel it especially when I'm visually analyzing a scene, as it's the speed at which I can control my eyes darting about a room. If I'm tired that slows down considerably.
The brain is just... so fascinating.