Noah Smith

Noah Smith is a mortal who attended Goode High at the same time as Percy Jackson. He was once a friend to Percy Jackson but later became his sworn enemy.

History
Noah was born in 1993 to Lisa Smith and an unknown father. Lisa was a teenager at the time she conceived Noah and wanted to have an abortion but her parents David and Janet Smith wouldn't let her.

At one point Lisa threw herself down the stairs in an attempt to abort Noah but this attempt failed and after that David kept Lisa restrained in her room.

Lisa Smith died in childbirth so Noah would up being raised by his grandparents. David and Janet probably recognized subconsciously that their daughter would still be alive if they had allowed her to get an abortion but they couldn't admit this to themselves.

Noah's grandparents were incredibly strict, even abusive towards him throughout his childhood. Partially they felt they hadn't been tough enough on Lisa (if they had then she might not have gotten pregnant) but partially Noah's grandparents blamed him for the death of their beloved daughter.

Personality
Noah Smith was a pretty straight-laced kid who didn't drink, smoke, do drugs and upheld a vow not to have sex outside of marriage. He always studied and usually got good grades. He also didn't have a social life outside of school. Noah's reputation as a goody two shoes caused him to get bullied.

There's a strong element of self-loathing in Noah's character, instilled in him by his grandparents.

Percy Jackson
The fact that Noah was bullied by other students is ironically what caused him and Percy to become friends in the first place.