For those who feel groggy after a "nap" I think there's a misunderstanding.
In this context taking a nap means: closing your eyes, relaxing your brain/whole body, and trying to empty your mind of all the thoughts that are usually racing around in there.
Most often you don't fall asleep in the first 15/20 minutes; and if you do it won't be a deep sleep that makes you feel groggy.
Practical tip: I use a timer App to make sure I know when to "wake up".
In this context taking a nap means: closing your eyes, relaxing your brain/whole body, and trying to empty your mind of all the thoughts that are usually racing around in there.
Most often you don't fall asleep in the first 15/20 minutes; and if you do it won't be a deep sleep that makes you feel groggy.
Practical tip: I use a timer App to make sure I know when to "wake up".