I Know For A Fact - When you talk like you’re the boss of the truth, even though

When you talk like you’re the boss of the truth, even though you're just making it up as you go.

I know for a fact that your mom is the best. Also, I know for a fact that you're the worst.

I know for a fact that you're lying. Also, I know for a fact that I’m telling the truth.

I know for a fact that the Earth is flat. Also, I know for a fact that you're dumb.