User Experience is no different than any other art based on technology, and as circumstances changes so does the User Experience. But to answer this thoroughly one must first ask what User Experience is. So what is UX, to the user? It’s behavior, reactions, feelings and emotions in everything that humans do – no matter the technology.
We use a hammer the same way we always have – and for unexperienced users of the hammer – the likelihood of hitting your self is very close to 100 percent. Bad design, some would say, but others would call it cognitive learning, i.e. to avoid pain, you learn how to hit the nail straight. And the hammer hasn’t changed in the last 100 years, neither have the User Experience of the hammer.
But a mobile phone has changed rapidly from the first heavy car battery sized mobile phones to today’s touchscreen, internet enabled light slick smartphones that attracts more and more users around the world. And as technology changes, so does the User Experience. Practitioners of User Experience would certainly try to convince Steve Jobs to let the iPhone follow the conventions of the web, since the phone had a browser. At least use the same UI as the button WAP phones back in 2005 2006, but Steve Jobs wouldn’t listen. Instead he quoted Henry Ford’s famous quote:
It's not about pop culture, and it's not about fooling people, and it's not about convincing people that they want something they don't. We figure out what we want. And I think we're pretty good at having the right discipline to think through whether a lot of other people are going to want it, too. That's what we get paid to do. So you can't go out and ask people, you know, what the next big [thing.] There's a great quote by Henry Ford, right? He said, 'If I'd have asked my customers what they wanted, they would have told me ‘A faster horse.’
This is an example of that it is possible to change User Experience and behavior – but in order to succeed, you need to figure out what users want, be sure that your users love what you’re doing and have the User Experience community accept the new style. That’s hard. For the most of us – this isn’t realistic. Instead we need to be updated, follow the technology industry closely and visit up to date sites, such as UX.SE, to not fall behind.
So you’re right: User Experience evolves over time, and to adapt you need to follow the right information sources to be up to date in your work.