[PragmaticPulp]

These phenomena aren’t completely absent in healthy people from time to time.

If it becomes a pattern you should check it out. If it happens from time to time over your life it’s not a big deal.

These phenomena are also common in young children as they grow up, too.

> That day I was sleep-deprived (3 hours of sleep on the night before), and had exercised a lot (I'm an athlete).

This is the obvious explanation. I know it likely goes without saying, but 3 hours of sleep is a major risk factor for health problems, including degenerative neurological disease if sustained. If you’re experiencing weird sleep/wake relayed symptoms after only sleeping 3 hours, the obvious explanation is sleep deprivation. Don’t even consider other explanations until you get back to a healthy sleep habit, which is hopefully soon.

Also, I’m sure you know this, but 3 hours of sleep is going to offset much or perhaps all of the benefit of intense exercise. Skip the gym and get some sleep if you must. It will be a net win.