Echo is a mountain nymph. Hera didn’t like her because Echo helped Zeus hide from her.
Hera made it so Echo can only repeat what other people say. She can’t say her own words.
Narcissus was very handsome and didn’t like anyone who loved him. He fell in love with his own reflection in water and couldn’t stop looking at it. In the end, he died or disappeared, and a flower grew where he was.
I think about how I look, if my hair is okay, or how I feel about myself. Sometimes I also think about what I want to do that day.
A narcissist is someone who only thinks about themselves. Narcissus in the story ignored other people and only liked himself, which is why he got into trouble.