I haven't practiced them in twenty years and I can still play them decently. If they start on a black key I need 3 seconds to play an octave in my mind, to doub

I haven't practiced them in twenty years and I can still play them decently. If they start on a black key I need 3 seconds to play an octave in my mind, to double check the first finger of each hand. Twenty years ago I didn't even need that.