I do like a siesta; I tend to have one most days. But I do them with a purpose (honestly!) and that is to clear my mind to help me better achieve the things I need to.
Often, like today, I also use them to let my subconscious mind come up with the answer that me 'far too clever for its own good' conscious mind can't figure out. So it isn't a nap, it is a team meeting with your inner team.