I was thinking today of all the different hats I wear in the various aspects of my life, and I've concluded that this results in one thing -- a large variety of different types of "hat hair". Hat hair is a very pretty intellectual concept, insofar as the hat hair implies a hat when the hat itself is absent. (And one can never observe hat hair with the hat present, unless it should be a transparent one.) Quite a daunting philosophical problem, in fact -- though since I am not a philosopher, it's not really a problem for me.