I have a few pet peeves but not that many...
First is when people think or say they're more mature for their age when they're really not... I have no idea why this makes me so annoyed, it just does

When people try to make one group of people sound superior to another group... especially sexism
People with OCD. My mum has it or is on the borderline of having it... I'm not an organized person by any means so it annoys me to no end when people never shut up about straightening up xD I forgive her though of course lol