I have been reading about the Japanese art of non-sleeping, and I find that I have been doing something similar for many years.
According to my sources (and I am yet to confirm this with any Japanese people, but aim to do just that today), the Japanese neither sleep (much), nor do they nap: instead, the practice the art of inemuri.
I’m not sure I fully understand the distinction (Tatsunori will no doubt clarify for me in our morning lesson, always assuming he is not doing a lot of inemuri during the lesson), but it seems to hinge on presence and absence. In Britain, if you take a nap, you generally absent yourself from various social and professional contexts; in Japan, by contrast, light dozing in public (on public transport, in meetings, at your desk, in an English lesson) is tolerated, even to a certain extent admired, since even though you are clearly exhausted from your various professional efforts, you have nevertheless made an effort to be present. Someone practising inemuri can snap to attention when required, but is otherwise permitted to drift for a few moments.
I have been summoned to a meeting later today, and if I am lucky with have an opportunity to deploy my own hyper-refined version of inemuri, where I am politely present, but also fundamentally absent (I am not permitted to say whether I conduct my lessons on the same principle). My eyes remain open, I nod, appear to make the odd note with my pen, I even occasionally make a constructive comment, but deep inside I am fast asleep. It is very refreshing, and a life skill.