But none of us choose or control our own history, even if we happen to produce more serotonin in response to certain stimulii - for genetic reasons.

The point at which 'willpower' (whatever that is - but I suspect it is a Learned Behaviour Disorder) is exercised, is preceded by a chaotic personal history. 'Willpower' has to be seen in that context. It is not something plucked out of thin air or applied by a secret switch.

One can change one's life, but only if that life is ready to be changed - like the psychologists lightbulb.

You can't be me, I'm taken