You know how in books and movies and stuff when a character can't eat nor sleep, they say that they're in love?

Why is that a thing?

Does it happen in life too?

What if the person just doesn't feel like eating and doesn't really feel hungry?

What if they can't sleep cause they're thinking of stupid stuff, like shipping or what they're gunna do the next day or what cereal they're gunna eat for breakfast?

In books and movies and stuff, when that happens, they immediately claim that the person is in love.

I dunno, I just find it weird :3