Timehop
A while ago I decided to uninstall Timehop for the reason that one should not live in the past. Every clichéd list of life lessons mentions as an advice not to try to hold on to what's gone by.
Recently, however, I thought better of it, because there's another thing Timehop's good for besides reliving memories. It's amazing to realise how indifferent I became to most of the things that used to matter the world to me at the time. Looking back it's funny to remember being all worked up on stuff that turned out to be picayune.
Consequently, it'd probably be smart to apply this experience to the present and just stop persistently brooding over whatever's on my mind. In a year I'll have a slew of other things to worry about anyway.