a know it all
A know-it-all is someone who thinks they’re super smart and won’t stop telling you they’re right, even when they’re clearly wrong. They don’t listen to anyone else.
'You’re all wrong! I’m the only one who knows the truth!' says the person who got the answer wrong on a quiz.
'I know the answer before the question is even asked.'
'I’ve been right about everything since I was born, and I will be right forever.'