If you want to know if someone is "real" tell them an obvious lie. A human will recognize it for what it is immediately, a cursed will not. They may look real, but they are not. Only real eyes realize real lies.
"Parallel lines have a lot in common, but they never meet. You might think that's sad. But every other pair of lines meets once and then drifts apart forever. Which is pretty sad too." a little bit of mathematical insight about life stuff.