What's the big deal about UX?

I've recently interviewed with a company looking for a multimedia designer, after some time in the interview they asked me about my work in UX. They were very excited to hear that I was interested in it and quickly asked me back for another interview with one of their IT specialists for a UX interview. I am amazed how you can go in to interview for one position and have the scope of your position change throughout the interview. I've been thinking a lot the past few days....what's the difference? Is the role changing? or just my title or approach changed..... What is the difference between a multimedia designer and a UX designer? 

UX =  the design of an interaction or experience that a person has with your product or service. Multimedia design = integrating multiple forms of media to help communicate information and ideas effectively. So what's the big difference? I'll conclude that every great UX designer should be a multimedia designer, but not every multimedia designer is a UX designer. A UX designer is going to fight tooth and nail to make sure that whatever experience people have is a good one. A UX designer will dive into the deep reaches of human psychology to find that right pitch at which a phone ping is exciting rather than stressful. A multimedia designer doesn't have near the responsibilities. A UX designer and a multimedia designer are measured differently; to a multimedia designer the question is "Did they receive all the intended information?" to a UX person the question is...."Did the person have a good experience as they received the information?". Now I think both have a similar goal, communicating clearly and effectively has its own reward, but at then end of the day UX designer is going to go the extra mile to follow up and say... did that make sense? I believe that UX people are writing the future. A UX person is as much a scientist as a creative. That's why I wanted to learn UX. 

Kalai Myrick