Hate is a very harsh word.
To hate someone, you have to give yourself permission to put aside all you know about mature and rational behavior. You must lose perspective and pity.
You must have been insulted, or personally embarrassed, or publicly rebuked by the object of your scorn.
Or else you’ve got an emotional connection with something, or someone, who may be threatened by the person you hate; say, the bank foreclosing on your best friend’s home–
Or the wife of a fascinating if flawed television character starring in one of the best written shows on television.