Do parents really have a favorite child???

I feel like as a parent we do but for me more specifically it depends on the day or period of time. My favorites switch on and off according to behavior but the most consistent would be my youngest boy, he's two years old. At two years old he's super smart, well mannered and occasionally rambunctious I look at him I see peace whereas my oldest really stresses me out. I can't be the only one of course my children don't know I have favorites, I dont treat my youngest better than the rest I just dont require much time away from him as I do the rest