Ambition

Strangely wrongheaded comment by Johnson: 'Every man is rich or poor according to the proportion between his desires and his enjoyments; any enlargement of wishes is therefore equally destructive to happiness with the diminution of possession, and he that teaches another to long for what he never shall obtain is no less an enemy to his quiet than if he had robbed him of part of his patrimony.' [Rambler No. 163: 8 October 1751]

But the name for a disproportion between desires and enjoyments is not unhappiness, but ambition. We are born into this condition, and without it would lack the motivation to achieve anything at all.