My brother is 6 years older than me and hates me. He cannot remember his childhood because of drug abuse so he conjured up his own narrative where he was the victim when in fact he abused me my entire life and resented me from the day I was born for no reason. It's a long story but when someone gets convinced they are less important than their sibling for whatever reason (real or imaginary) it causes some deep seething anger and pain and need to restore ones ego.