My father, an industrial scientist, took a lunchtime nap every day throughout his career. He was quite brazen about it... even took his nap outdoors during the summer months.

I really benefit from a little nap at lunch time. I start my nap with a book or my tablet computer on my lap, to make it look like I fell asleep by accident.

I personally think that napping is kind of a skill that has to be learned and practiced. Even babies have to be taught how to nap on demand.