Do we bounce back quickest when life hurts us the most?

Yes. Often we bounce back from painful events more quickly than we would guess:

Intense hedonic states trigger psychological processes that are designed to attenuate them, and thus intense states may abate more quickly than mild states. Because people are unaware of these psychological processes, they may mistakenly expect intense states to last longer than mild ones. In Study 1, participants predicted that the more they initially disliked a transgressor, the longer their dislike would last. In Study 2, participants predicted that their dislike for a transgressor who hurt them a lot would last longer than their dislike for a transgressor who hurt them a little, but precisely the opposite was the case. In Study 3, participants predicted that their dislike for a transgressor who hurt them a lot would last longer than their dislike for a transgressor who hurt someone else a lot, but precisely the opposite was the case. These errors of prediction are discussed as instances of a more general phenomenon known as the region-b paradox.

Source: The Peculiar Longevity of Things not so Bad” from Psychological Science

Why is this?

We rationalize big problems, not little ones. Because discomfort must pass a threshold to trigger rationalizing, often little pains end up hurting more and lingering longer than larger ones:

People rationalize divorces, demotions, and diseases, but not slow elevators and uninspired burgundies. The paradoxical consequence is that people may sometimes recover more quickly from truly distressing experiences than from slightly distressing ones (Aronson & Mills, 1958; Gerard & Mathewson, 1966; Zimbardo, 1966). A wife may do the costly cognitive work necessary to rationalize her husbandâs infidelity (ââI guess men need to try this sort of thing once to get it out of their systemsââ) but not his annoying habits (ââI guess men need to experiment with leaving their dirty dishes in the sinkââ), and thus the wifeâs anger about her husbandâs disorderliness may outlive her anger about his philandering.

And:

Contrary to their own predictions, participants in our studies disliked least those who had hurt them most. This paradox arises because intense hedonic states are especially likely to trigger the psychological processes that attenuate them. Because people are unaware of these processes, they mistakenly expect more intense states to last longer than less intense states.

One of the authors of this study is Harvard happiness expert Daniel Gilbert. His book is Stumbling on Happiness,