You know how snakes and other cold-blooded animals' blood temperature changes with fluctuations in air temperature? If it's cold out, their body temperature is colder, and when it warms up, so do they.
Well, that's how I am too--except with my mood and the seasons. When it's cold and dark and dreary, so am I. Now that spring is here, I feel like a genuinely different person. Even though my skin is still so ghostly white.