The bigger thing that I am speaking of though, remains true, we are a part of the earth and not separate from it. If you think things in our environment (and even things outside it like the moon) do not effect us, it makes no sense in a quantum physics sort of a way. Too many women (in particular) feel the full moon coming on and there is the menstration correlation as well. Of course there are many other examples we see in our lives that show we are not separate from Nature, we are born from it. Just like an apple tree "apples", the earth "peoples". Allan Watts said that and we don't lose the connection...

The smart money says it's coincidence. In Science and the Paranormal (1983), astronomer George O. Abell writes, "The moon's cycle of phases is 29.53 days, while the human female menstrual cycle averages 28 days (although it varies among women and from time to time with individual women); this is hardly even a good coincidence!