Winter and the changing of the seasons

I am so influenced by nature. I know this, but still I think, probably like most people, that I'm above being affected by it.
Just a few weeks ago, when the nights really started drawing in, I realised that almost everyone I spoke to was saying how terrible they felt; how low in energy and motivation (even people I'd usually turn to to pep me up). Then I heard an article on the radio saying that new research clearly shows that we are all far more affected by the changes in the amount and quality of light than is generally acknowledged. What our bodies want to do, is curl up in front of the fire and stay inside in a safe warm cocoon.