Why are parents such egomaniacs?

I wasn't sure of another word to put for egomaniacs, but I guess that works. No matter what I do, they are always right and I am always wrong. I don't think in the 9 years since I've moved here that i've been wrong more then 3 times maybe. If its about computers ( which I get 80's+ for grades in ) and they don't even know what, youtube, twitter, itunes, facebook, wikipedia, etc. is ( plus how to type/ anything about the control panel or its functions ) I am still the one who's wrong. I get yelled at so much for being right about the computer for example. Just the other day the ping was sky high for the hole day and they thought it was my fault even though i've played the game for 2 years with no problems whatsoever. Not to mention that they updated programs that shouldn't be updated ( due to our computer ) and as soon as they did that 1 min later the games all didn't work. They would say " Ohh its the servers " or " stop downloading things then ( even though I don't download anything ) " etc., even though they don't even know what that means.