It's always when you least expect it. Or when you don't want it. Like, genuinely don't want it. Actually, saying you don't want it isn't strong enough a sentiment. Instead, "it" always happens when "it" is the worst idea in the whole wide world of bad ideas.
There you are living life the way properly indicated for you. You're stoked some days, bummed other days and, the rest of the time, you slink your mouth into a half-grin suggesting, not so much complacency but, a this'll do mentality. No big deal. That's life. But then something happens to shake everything up. Something that tests all the absolutes you've placed on yourself about the shape of your life. It's as if every little rule you've made unnecessarily heavy starts drifting away, helium-balloon style, until you realize you can't reach rationality no matter how high you stand on tippy-toes. Which is spectacular. And scary. So you fight it, no matter the dullness of your balloon-popping blade and the futility of your effort.
Maybe you explain to whoever is most interested that this deck just isn't the one you planned to play. According to you. Even if the hand looks pretty awesome -- maybe even more awesome than what you were anticipating -- it still isn't right. According to you.
So you fight this thing simply because it was not, as you imagined, in the Grand Scheme of Things. Plus, quite frankly, you'd rather not deal with this now. Maybe someday, but not now. Never now. But then it showed up and shocked you with its HelloHow'd'yaDo and you can't get it out of your mind. Still, you try to stay true to a stagnant past view and, with all the valor you can muster, you fight and fight and fight until your narrative is no longer about the thing itself but, instead, about how much you're fighting against the thing when, really, it could all be so easy.
Some things like, say, I dunno, cancer and grammar and marriage equality really deserve a good fight. Absolutely. Keep on keepin' on. But then, c'mon, other things like, say, I dunno, anything involving how you arbitrarily think your life should unfold deserves to be unhinged from attachment and expectation. Some things really are rare and special and surprising.
But fight if you like to fight. The thing -- whatever its proper name or title or face may be -- will just begin to go with the flow of the tide while you exhaust yourself swimming counter to the current just to prove a point you've already forgotten.