This State Of Confusion

At times, we all go through this situation. You take a short nap in the afternoon, and you end up waking up at some point in the late evening. That happens because your brain completes a full cycle of sleep including a few hours of deep sleep a.k.a. Theta state. Usually, during short naps, your brain doesn't enter the deep sleep stage. It regains consciousness right after the REM phase a.k.a. Rapid Eye Movement.