Sleeping in the middle of the day, in the middle of the street is very usual in Vietnam, I always admire how peaceful people just let themselves go to the world of dreams, without caring about the world around them. Vietnamese people wake up so early, at 5am they're walking or running in the street, moving their arms around, doing exercice before it gets too hot. I also admire that, damn so much energy while I'll be forever in my bed. So it seems some of them don't really have a proper night, they sleep when they can. Nap by nap.