Synchronised peeing

 I've noticed something weird whilst living in this flat. 

Previously, I'd lived in an apartment with no-one above me, or to the left and right of me either. It was the quietest place I'd ever lived in even though it was a two-minute walk from the station. Overlooking the garden at the back, I could sleep without earplugs. It was blissfully peaceful.

In this flat, however, I have flats on all sides of me, including above me. And although the neighbours are pretty quiet, I do hear them move about from time to time and I can hear when they use the toilet.

What has struck me is that very often - both during the daytime and even at night (even when it's 3 in the morning) - when I have to use 'the facilities', then I hear one of my two neighbours (a married couple) above me flush the toilet at the same time.

I find this weird. Whether I get up at 3 in the morning (or 4 or 5), I can be pretty certain that either Mr or Mrs B. will be in the bathroom at the same time. During the daytime, I could understand it, but in the still of the night?

A good case of synchronicity if ever there was one.