Try to mentally "restart" yourself. By this, I mean try to reset, at least temporarily, all of your thoughts: your problems, your future goals, your conceptions of your Self. If successful, you'll feel lighter, as if you were at the beginning of a journey and not midway. I think this feeling is universal and you probably know what I'm talking about. That rare moment when the world seems fresh and new. It's elusive but powerful.

Some methods that seem to work, for me at least, are: meditation, immersing yourself in a particular work of fiction (especially a sci-fi movie at the cinema), turning off your phone and Internet connection, and getting lost in a new city.