It is a choice but it's also a series of choices. The analogy with physical exercise is appropriate - after a long period of sloth trying to be more active can

It is a choice but it's also a series of choices. The analogy with physical exercise is appropriate - after a long period of sloth trying to be more active can feel incredibly difficult. Subsequent attempts (usually) are gradually less hard. This is the whole "excellence isn't an act but a habit" thing, usually attributed to Aristotle.