That he might, by force of will
He imagined that this was an ability he shared with most other people
Although some people might have made mistakes
They had also molded their faces according to some ideal
They may have picked an ideal appearance
And that through the years
Gradually his face would change it's shape
They may have arrived at an appearance
A more hooked nose, wider, thinner lips
Or somewhere in the back of his mind
Beady eyes, a larger forehead.
By keeping an ideal facial structure fixed in his mind
Cause his face to approach those of his ideal
Maybe they imagined that their new face would better suit their personality
To fit the new appearance
The change would be very subtle
Some may have gotten half-way there, and then changed their minds
That bears no relationship to them
Or maybe they imagined that their personality would be forced to change
It might take ten years or so
Based on some childish whim, or momentary impulse
This is why first impressions are often correct