Factotally
When you know something is true so well it might as well be tattooed on your forehead and you can't stop telling people, even if they don't want to hear it
I know the Earth is round so well it's like it's tattooed on my forehead and I tell everyone I meet. I'm a factotally annoying person.
I told my dog the sun rises in the east and he looked at me like I was crazy. I'm a factotally stubborn person.
I told my mom the sky is blue and she said I was right. I'm a factotally confident person.