No, you are correct.
That is the reason why Seasonal Affective Disorder is very real and can be treated with the right kind of light bulbs. Full spectrum, pretty cheap and you feel great all winter.
Living in Idaho in the winter makes it harder, but I definitely know I need to find some vit D/sun/fresh air when I start to sink into the mid-winter doldrums. Exercise helps too (’cept I’m shackeled to my computer :).