Have you ever hated someone so much, the very thought of them makes your skin hot with rage and your fingers and toes curl? The sight of their name makes your face turn sour and you would rather sit in a vat of spiders than listen to them speak. A hatred like this, especially an immediate one, does things to you. That person won't get out of your head; no matter what you try. 

You constant obsess over their flaws to distract yourself from yours. In them, you see everything you hate in yourself. You're almost too similar.

Not that you'd ever admit that.