Having ridden this rollercoaster myself, it seems to vary from person to person but most of the people I know have some degree of "a", and can choose "b". You

Having ridden this rollercoaster myself, it seems to vary from person to person but most of the people I know have some degree of "a", and can choose "b". You spend some decades thinking "counting sheep" was meant figuratively; you discover that was not the case.