If there was ever a phrase by which to live life, it should be this: shit happens. I don't deny that WWJD or 'one door closes, another opens' are aspirational and can provide a glimmer of hope in some dark times, but to me nothing quite encompasses the world's misfortune as much as those two simple words. The played a small but important role in the film Forest Gump, and even before that they were words I knew to respect and use frequently.
Shit happens isn't about trying to find light in a dark situation, it's about accepting that sometimes life is just going to be dark for a while, and that you'll probably stub your toe a few times whilst fumbling for the light switch, and when you do find it, the light is one of those old energy-saving bulbs which were suddenly immediately popular in the early 2000's, but took about half an hour to actually produce any substantial amount of light. It's about acknowledging that life won't always be dark, but when it is dark there's probably very little you can do about it by yourself. You may as well embrace the darkness, kick a few table legs, and swear at nothing in particular. Above all, shit happens is a sigh of relief which lifts all responsibility off your shoulders. Yes, it's quite dark, but is that entirely your fault, probably not. Will curling into a ball and crying somehow magically turn the light on? Probably not. Will the light even work after you wade through the shit and eventually find it? Who knows. Because life, despite everything we try so hard to believe, really isn't ever entirely in our control.
It's not all doom and gloom, mind you. The point of this phrase is not to depress or agitate life's harsh realities, but to accept the bad as it comes, and know that everything is temporary. Shit happens should always be spoken with a smile, and knowledge that eventually things will get better.