You ever say "how's it going?" to someone as you pass, and they give you a multi-sentence response? It isn't bad so much as unusual, and the classic etiquette here makes a lot of sense – don't unload on people who are engaging in quazi-mandatory small talk. They're acknowledging you, and if you acknowledge them, it invites them to start the conversation they signaled they wanted to start. Give them a couple seconds to figure out whether they're just being friendly or want to talk, just say "it's all good" or "nothing much" or similar.
But, of course, if you've ever felt trapped by this, you fell into a very funny and ironic trap. You have something to do, and they didn't read signals enough to know you wanted to go do it. But of course, you did the exact same thing to them! They were doing something, you interrupted, even if just for a moment, and diverted them. It's not completely symmetric, because our expectations say people should give short answers, and it's generally cool to say "what's up?" – but it's close, and being stymied and flat-footed by their reaction is still quite silly.
Today, though, we want the most ironic frustration, when empathy should be so easy as to be automatic. Like when you're accidentally blocked out of a 5-ish person conversation because other people keep jumping in before you. The group is too small to start side conversations unless the main one is boring, and you have all these juicy, interesting things to say that you just... can't.. get.. in. But the reason you can't is because everyone else feels the same way! And you don't disagree with them, or you'd start a side-conversation with someone closer to you, knowing you'd both be okay with ignoring the less-interesting main track. But you can't – the main conversation is interesting, and you wouldn't want to distract from it – if you could just get the comment in first. Very frustrating, and extremely symmetric – a strong contender.
But I think our award of the day has to go to road rage. I don't drive, but I've seen how people get – maybe not rage, not for most of us, but they get involved. But we all make mistakes. And road rage is typically incited by someone in a rush – going on the same street as you! You have somewhere to be, and this maniac is doing THAT! But of course, not only do they have somewhere to go too, they're going a similar place. Remember, they're on the same road as you? And they're out of control? You're the one giving a tone and admonishing someone in a different car. It is near-peak frustration for many people (outside work), and it's almost better than perfect irony. You aren't just angry at someone so similar to you, but angry at them for using options you'd like to keep available to yourself. Of course, when you slow down on the freeway and change three lanes to take an exit you almost missed you really needed to do that. It sucks but it isn't like you deserve to be admonished – you know how difficult it would have been to miss the exit.
Of course, we should exercise our empathy even when it isn't quite so trivial. We should see things from other people's perspectives – not just our own transposed into their body. But these moments are things we should laugh at, the little eddy currents and traps we all find ourselves in for split seconds. Maybe if we pay more attention to them, we'll become more thoughtful people?