At 16 Bonaparte was trained as a soldier. So he dreamed of conquest.
At 27 Bonaparte was an officer of a country at war. So he started to fight, and thus conquered.
No mental disorder there, career.

If one of the boy outside started speech, was good at that, and dreamed of being US President, would you send him to hospital for treatment or to university to learn his trade ?
When De Gaulle said he was France, would you have send him to asylum or to BBC ?