I just want to be myself today

Today as my son was getting ready for school he decided "I just want to be myself today" which meant please don't Mohawk my hair I'm going to leave it down. I just want to be myself today, I didn't realize he was being someone else. Are there days when we all feel like saying to the world I just want to be myself today? For me that would be staying home with my Pajamas on until Noon or so and then changing into my most comfortable cloths which sometimes consist of an upgrade to jogging pants ( which I never go out in public in). Mondays are usually my "I just want to be myself today" day so if you want to visit you could be in for a surprise. What day is your "I just want to be myself today" if you have one and why?