I don't know about 'angsty' back stories, but my players tend to create characters with rich personality quirks, seemingly designed to annoy one another to maximum effect, creating a sort of existential "No Exit" a la Sartre.
One of my current players, Chris, is playing a human Magic-User (what we call a wizard in 1e AD&D land). But, he was raised by goblins as a foster child. Not 'mines of Moria' type goblins but living in the goblin reservation in the city 'civilized' goblins.
The character's name is Jim Smorkle, and he is nearly completely unaware of what actual human/elf/dwarf polite society is like. As a magic-user, he carries with him a false beard. He puts on this false beard for spell casting because he truly believes the beard is important for doing "wizard stuff".
Goblins are only 'tolerated' in his origin city, rather than accepted, which is still a big step ahead of most other 'civilized' places. In the time of Jim Smorkle's foster grandfather, the goblins quietly began to infiltrate the city's underbelly seeking a peaceful place to settle. They usually went about at night, or if during the day, with cloaks and disguises to TRY to pass as some sort of demi-human.
Living in the fringes, they slowly worked their way into the extermination business. Rats, bugs, and such. Also in waste disposal. Also, setting up a legitimate shop to sell non-magical disguises! (a skill they honed out of necessity). By Jim Smorkle's time, they were the largest organized crime syndicate in the city, dealing with extortion and protection rackets with the currency being other people's dirty secrets.
More than tolerated, they are a fixture, as no one wants to handle the legitimate extermination nor waste disposal jobs either.
Tolerated, but still not quite ever accepted into 'polite' society.
The extended Smorkle clan was DELIGHTED to discover their adopted son possessed high intelligence and magical talent, so they could FINALLY have a family member with wizarding skills! His foster brothers, goblins not being allowed bear the wizard college, even disguised themselves as humans (one goblin upon another's shoulders in a trench coat) so that they could sneak into his graduation ceremony!
Lol, I might tell more of it, but this was all back story! Not all fleshed out at character creation, but developed as the character's personality emerged through pkay.