Thread: Afternoon Naps ~ R.E.M?

It’s often advised that one should attempt to induce a lucid dream during an afternoon nap. Furthermore, it is apparent that the most vivid dreams occur during R.E.M. Thus, I assume that R.E.M cycles often occur during afternoon naps.

If this is so, then my question is: Why do we have a R.E.M cycle during the afternoon?