The attitude he describes is one more associated with Eastern thinking. If I had to venture a guess, I'd say it's closest to Zen thinking:
A man traveling across a field encountered a tiger. He fled, the tiger after him. Coming to a precipice, he caught hold of the root of a wild vine and swung himself down over the edge. The tiger sniffed at him from above. Trembling, the man looked down to where, far below, another tiger was waiting to eat him. Only the vine sustained him.
Two mice, one white and one black, little by little started to gnaw away the vine. The man saw a luscious strawberry near him. Grasping the vine with one hand, he plucked the strawberry with the other. How sweet it tasted!
Zen parables often can have many meanings, but one I would point out is that, if the man were to fret about his situation, it would eat him up inside. In the case of this man, it would prevent him from enjoying the last strawberry. In the case of the Hulk, having an anger (about losing control to anger) eating him up inside would have more disastrous consequences.
This is the lesson for negative emotions. Negative emotions breed more negative emotions. If you are the Hulk, and negative emotions are really really bad, the only way to be free is to embrace them, smile at them, and from time to time, smash some things.