There are also examples in the opposite direction. Heartbeat and breathing are active 24 hours a day. People can keep playing for hours. So it’s not like any human activity is necessarily limited to short intervals. I guess the proper question would be: “Why is willpower (sometimes) spent so fast?”
Which I guess cannot be answered until we look into details of what constitutes “willpower”. (And we may find that actually different forms of “willpower” consist of different components—maybe even that different people use different mental activities for dealing with the same kind of problem—so using a single word for all these meanings is confusing.)
There are also examples in the opposite direction. Heartbeat and breathing are active 24 hours a day. People can keep playing for hours. So it’s not like any human activity is necessarily limited to short intervals. I guess the proper question would be: “Why is willpower (sometimes) spent so fast?”
Which I guess cannot be answered until we look into details of what constitutes “willpower”. (And we may find that actually different forms of “willpower” consist of different components—maybe even that different people use different mental activities for dealing with the same kind of problem—so using a single word for all these meanings is confusing.)