The human animal originally came from out-of-doors. When spring begins to move in his bones, he just must get out again. Moreover, as civilization, cement pavements, office buildings, radios have overwhelmed us, the need for regeneration has increased, and the impulses are even stronger.
Remembering what you've been through and how that has strengthened your mindset can lift you out of a negative brain loop and help you bypass those weak, one-second impulses to give in. Even if you're feeling low and beat down by life right now, I guarantee you can think of a time or two when you overcame odds and tasted success.