All people are different and I'm the opposite when it comes to cloudy days as they make me more sad and depressed but when the sun starts shining I am more upbeat and happy and in a much better and happier mood.
When it's cloudy or rainy out I feel like doing nothing at all and want to just sleep and I move slower during those days.
But when the sun is shining I feel much better and more motivated to do things that I want or need to do.
My friend is one of those people that gets happier on cloudy and rainy days and he's not even sure why the cloudy days make him happy.
But he says it's probably because the sunlight is usually too hot outside during the summer which causes him to want to stay inside more to avoid the heat.
But when it's cloudy and dark it's much cooler so he feels more uplifted and is outdoors more too.
I'm not entirely sure why either but I can say for me the sun not shining prevents me from getting the needed vitamins which boosts feel good hormones in our bodies and when that sunlight is gone the hormones are not being produced and so I feel sad.