Imagine a scenario

You've been on the other side of the planet, inventing games with children and finding the space you need to be honest with yourself. You've spent some time marveling at how comprehensively inept you've been and started coming to terms with not being nearly as much of a saint or a cunt as you often believe. Now you're grinning with contentment at a used book with a trashy title in a 3'rd class seat about a mile above certain death. You're excited to see your friends and your family but slightly less excited about reexamining the value and purpose of those relationships. You're excited about starting a new adventure, but significantly less excited about the long stretch of unemployment that will certainly preface it. For now, you're slowly sipping a cup of coffee and trying to convince yourself that this can couldn't possibly hurtle out of the sky with you on it, because you're far too important to the social advancement of the human race to die without making a splash (so to speak). About halfway through the coffee and barely past take off, the guy next to you sighs in exaggerated frustration over some exotic derivation of a sudoku puzzle and starts clicking his pen.

“frick”, you mumble inwardly. And you wonder how many clicks it'll take for his brain to remember that other people exist and up shift into empathy. Part of you knows that this guy isn't responsible for your emotions. Part of you knows he shouldn't have to read your mind and guess your emotions and put your preferences above his own and basically lay prostrate before you like some sniveling serf at the court of a tyrannical toddler. Part of you knows that it's incumbent upon you to express your own desires and negotiate for mutually satisfactory solutions. So part of you knows that the only question left is what you should do about it. But another part of you is mustering its indignation and asking, “What should I do?!.  What should he do?! What kind of a thoughtless asshole allows himself to produce a sound that's as stereotypically irritating as nails on a chalkboard in a space packed shoulder to shoulder with strangers with no escape?!”

Your brain is still addled with the lingering side effects of religiosity, so you immediately start shaming yourself. Isn't the readiness with which you become irritated over trivial things like pen clicking itself a character flaw? I mean, specks and planks and all that, right? You should have compassion for him. Aren't people's quirks the very things we come to love about them as our relationships mature? If this guy was an attractive woman, you might find the clicking charming or even sultry. If he was some precocious ten year old, puzzling over his math homework, celebrating with muffled excitement over each new problem he solved, you'd probably find the clicking adorable. You'd want to snatch him up and raise him as your own. You can just see yourself getting up before the dawn, full of joy and purpose. You're packing his lunches and preparing for the years of litigation to win custody away from his charmingly jet set but disinterested parents. You're going to soccer games and PTA meetings and pirate themed birthday parties and leaning over to whisper to your attractively plus sized wife about how much your heart is aching with the love you have for your little family and...

“Oh my God, he is still clicking that fucking pen!”

“Seriously, Guy?! Do you have absolutely no consideration for the well being of others?! Our species evolved a desire to exhibit a pattern of reciprocal altruism when we were still wandering barefoot after berries and buffaloes in extended kinship groups on the plains of the Serengeti! Is your genetic heritage that far behind the curve?! Somebody call the Discovery Institute. Apparently I've found the missing link!”

OK, so maybe that was a bit harsh. It's not like he's callously sauntering past a rape in progress. He's just fidgety. And if it weren't his pen clicking getting to you, it would probably be the next guy's humming or somebody else's slurping. What kind of a megalomaniacal moron are you that you consider it both possible and desirable to control every insignificant detail of your environment?

but before you can finish the next thought, you stop yourself, because you're still shaming yourself for your emotions, instead of deciding to have the courage to deal with the situation. And you realize that developing virtue isn't going to be as romantic as you expected.