When I was in elementary school, we could buy hot lunches on a tray with a mini-carton of white milk
In fifth grade, my class went on an overnight trip with all of the other fifth grades in all of the district's schools. During that trip, I discovered that the other elementary schools cafeterias had chocolate milk -- not just white milk -- with their lunches. During the three lunches we received over the trip, I got -- and loved -- the chocolate milk.
After we got back to our school, we were back to plain white milk. It was ok -- but it was also not ok. We had seen how things could be. We had gotten a glimpse of something better. It was difficult to return to normal lunches knowing that Chocolate Milk was still out there.
It is an interesting part of life that once one can see how it could be, it is difficult to imagine how the past (which may have then been acceptable) actually was acceptable. Part of striving and thriving, I suppose.