How Important is Sound? Really?

[ReduxInflux]

hi. i have amateur ears. well...virgin ears if you want to call them that to the true capability of blu-rays output of sound. i dont understand the technical specs or pcm or compressed vs. uncompressed or true hi def, etc. and really...i don't care. but maybe if i was well informed, i might start caring. but thats besides the point. so i have a question... and i'm looking for elementary answers. pretend i'm a 3rd grader when you're explaining it to me

sooo...my question is this: what in the world is the difference in sound quality between your your HD set-up - whereby i'm assuming you have a Blu-Ray player connected via HDMI and outputting audio to your supreme sound system ... vs. my dad's 37" toshiba CRT from the 90's thats connected to a regular DVD player thats outputting in surround sound through a JVC receiver that utilizes 3 front speakers, a subwoofer and 2 rear speakers via component cables....this sounds good to me. but i don't know any different? how does sound improve in quality? picture to me is obvious - resolution, response time, sharpness, color, etc. etc....but sound? its really a vague concept to me. there's poor sound for sure...but then there's good sound. and after good...i dont know how much better it gets and how much its worth? (im tempted to buy a $100 surround sound set at Wal-Mart ...if i can find one that will just do the job). i dont understand why top-of-the-line audio sets are selling for $700 and up. i mean...is there really a huge difference? and if so what? thanks for your help and your time. consider me danielson and you mr. miagi...