It’s okay to be indifferent, perhaps it’s natural for humans to be ruthless. If your friend is so self-absorbed as not to notice he is about to step into poop,

It’s okay to be indifferent, perhaps it’s natural for humans to be ruthless. If your friend is so self-absorbed as not to notice he is about to step into poop, then he will step in poop, just not while you’re around to smell it. Buddhists are the most indifferent yet compassionate people I know because compassion requires impeccable mental silence at all times, and after so many years you realize it really doesn’t matter if your friend knows he’s about to step in poop or not. All that matters is that he learns his lesson, that he was too important to not notice the poop himself, and that’s not something you can tell him, he has to learn that lesson himself.