Deferred Happiness Syndrome:

The common feeling that your life hasn't begun, that your present reality is a mere prelude to some idyllic future. This idyll is a mirage that'll fade as you approach, revealing that the prelude you rushed through was in fact the one to your death.

“One day I’ll make it.” Is your goal taking up so much of your attention that you reduce the present moment to a means to an end? Is it taking the joy out of your doing? Are you waiting to start living? If you develop such a mind pattern, no matter what you achieve or get, the present will never be good enough; the future will always seem better. A

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What all of these examples have in common is that the former require less activation energy, feel good immediately, and feel crappy later on. The latter require more work up front, feel not so great immediately, and feel wonderful later on.