Seems like a lot of people where I live start their work from this hour; I presume they are either merchandisers that deliver milk to the nearest supermarkets or lorries that need to get delivered before the morning heavy traffic that schools cause on a daily basis.

I guess in my case, the combination of low lights at night, near complete silence all over the place, and hearing crickets outside the window during my coding hours, it helps immensely to get absorbed by the mystic call of zoning lol!