It varies. If you have this all the time, I’d suspect your sleep duration is not aligned with your sleep cycles. I’ll be more confused if I had dreamy sleep, I’ll be more confused if I wake from REM or deep, and I’ll be very confused if I awake from a dreamy sleep during REM or deep. I don’t think I forget I’m human, but it can take a second to adjust to not having a dream reality. I’m definitely, often enough, entirely confused as to where I am for a moment.

However, this effect is lessened when I awake from light sleep. It feels more natural. There’s a lingering sleepy feeling, but it somehow feels like I’m well rested, even if it’s a short sleep. Sleep cycles are typically 90 minutes (light-rem-deep-rem-light). 6 hours isn’t great, but waking is acceptable. 7.5 is good enough for me. 9 is too much commitment to test.

Ironically, when I drink until bedtime, I can sometimes wake instantly if the timing is right. However, it’s like a low power mode. I’m alert, but lazy. Like I just blinked away my entire sleep. Alcohol tends to prevent REM and disrupt deep sleep.