Sir Thomas Browne:

I am the happiest man alive. I have that in me that can convert poverty to riches, adversity to prosperity, and I am more invulnerable than Achilles; fortune hath not one place to hit me.

Adam Smith:

The great source of both the misery and disorders of human life, seems to arise from over-rating the difference between one permanent situation and another. Avarice over-rates the difference between poverty and riches: ambition, that between a private and a public station: vain-glory, that between obscurity and extensive reputation. The person under the influence of any of those extravagant passions, is not only miserable in his actual situation, but is often disposed to disturb the peace of society, in order to arrive at that which he so foolishly admires. The slightest observation, however, might satisfy him, that, in all the ordinary situations of human life, a well-disposed mind may be equally calm, equally cheerful, and equally contented. Some of those situations may, no doubt, deserve to be preferred to others: but none of them can deserve to be pursued with that passionate ardour which drives us to violate the rules either of prudence or of justice; or to corrupt the future tranquillity of our minds, either by shame from the remembrance of our own folly, or by remorse from the horror of our own injustice.

Dan Gilbert (about 20m into the talk):

In other words, yes, some things are better than others. We should have preferences that lead us into one future over another. But when those preferences drive us too hard and too fast, because we have overrated the difference between these futures, we are at risk.

When our ambition is bounded, it leads us to work joyfully. When our ambition is unbounded, it leads us to lie, to cheat, to steal, to hurt others, to sacrifice things of real value.

When our fears are bounded, we're prudent, we're cautious, we're thoughtful. When our fears are unbounded, and overblown, we're reckless and we're cowardly.