Some time ago I went to Japan on a 10 day business trip. I was wined and dined and fêted pretty much every one of those days and sushi, almost invariably, featured as a part of every menu. The quality was good, better than what you can get in London, but I soon started to feel a bit... "Meh" about sushi and wondered if I had actually gone off it.
I had one day to myself before I needed to return to the UK and my father in law invited me out for a meal. My heart sank when I learned it would be a sushi restaurant. Thank goodness he took me there.

The fish doesn't melt in your mouth, it's something else. In your life you've been kissed and then you've REALLY been kissed, and it's the same with sushi, when it is good it is like the most fragrant, delectable person you can imagine sliding their tongue into your mouth. Why it is that one piece of sushi is a piece of fish on top of seasoned rice and and another is an utterly sensual experience that feels like oral intimacy way too pure to be obscene (although it feels as if it should be) is not something I can explain. And the sushi restaurant my father-in-law took me to wasn't even close to being best in class (more a great business class when you are used to economy).
Personally I am happy to keep exploring (whenever I can) high end sushi at this lower tier and if I ever start to feel jaded it will be then that I might consider visiting a place like Sukiyabashi Jiro (first class cabin). And it isn't just the expensive fish that can provoke this minor extasy, I still remember the sardine sushi I ate in Shiogama two years ago, it was exquisite, am lucky that my husbands families are fish experts as choices I wouldn't make for myself are often the most memorable.

I see it with other cuisines, those who have never tried a good Jamón Serrano in their lives just leapfrog immediately to the most expensive Jamón Iberico they can find without giving themselves the opportunity to learn and savour what makes this kind of meat special and how geography and diet and curing, etc influences the texture and flavour. Cutting out the learning/appreciation curve and going directly to the "good stuff" also (IMHO) means you are less likely to fully appreciate the experience.