It can be found that ones free will/may stay intact more so when they are young and have a very active life; bringing young children up, working a full time job, even nursing a member of family or someone else, or doing some kind of charity work which may be a very needy cause which may take up much of ones time, and many more.
But when one has a bit more time for themselves maybe as they get older and wiser, depending upon what the divine requires of someone they may or even will find this is when their Karma may/will show itself, and it can do so through their health situation which will run in tandem with their Karma, and this is the time when the person will have to take stock and attempt to work out what is their illness or age problems and what is their karma coming into effect, because this is what takes place much of the time.
Also this is a time when the Divine may implement the taking away of ones free will, upon what ever level he so desires to have his demands carried out. (This is just a short word of guidance given through experiences, my experiences and no doubt other peoples also, and I have been guided at this very instant by the divine to keep this explanation short). I know why but that is another story.