Americans believe that Europeans use their forks upside-down with meat and with the wrong hand, and they believe the same about us. Sponge-headed Scienceman gave me an old copy of In Small Things Forgotten by the archaeologist James Deetz, who explains how this happened. Forks were not used in England until the 17th C and America until the 18th. ("What is this Italian trash?" my eldest used to say at Society for Creative Anachronism events, throwing his fork over his shoulder.) Prior to this, food was conveyed to the mouth by a knife with pointed end, with a spoon, or with fingers. When the fork came in in England, the blade no longer needed to be pointed, as the meat would already be on the tines. If one is stabbing other foods on the plate such as vegetable or fruit, the tine-down position is more efficient as well. Knives with rounded tips came into fashion in England.
Americans did not make much cutlery at this point and most of their table knives were imported from England. It became more difficult to convey food to the mouth, and we developed a mixed-practice of more fingers, inefficient round-tipped stabbing, and especially, more pushing and scooping of foods onto the spoon. A spoon, one can easily visualise, can only be used with the bowl up. It was about two generations before forks became common in America, and everyone had by that time learned a good deal of scooping and pushing in order to eat. It was certainly possible that when the fork arrived we would have used it in the European way - we do set them on the left and we cut in nearly the same manner. But we didn't, being very used to the motions of scooping with the right hand, and so transferring the fork to that hand repeatedly (and inefficiently) throughout a meal became the norm. We stab a bit less as well.
It is a cultural intuition we have developed, the correct or usual way to hold a fork. It could change. We sit more upright to eat, the Chinese lean over very close to the plate. They have been slowly trending to the Western posture when out in the wide world, but there are a great many of them, and customs may trend the other way. In a hundred years Americans might be seen as having this eccentricity of eating upright while the rest of the world leans over in imitation of the Chinese.
Our customs of formal glassware, silver cutlery, and "good" china have changed almost entirely in my lifetime. We have several times had the conversation with people our age how seldom anyone uses their good china anymore. We have tried to make an effort to use ours more often, thinking it a shame that it has gotten so little use over the last forty-plus years. You can buy entire sets of good china for a song these days, as people inherit second or third sets and are running out of children to bequeath them to. Very few families set a formal dinner every Sunday anymore.
It is not only the dining custom that has changed, but the bridal customs as well. I remember being roped into animated discussions at my wife's sorority house in the early 70's of women choosing their china and glassware patterns. I had little opinion, and I now think the one opinion I did have was wrong. I did not want the ornate Chinese dragons looking at me while I ate and vetoed them. In retrospect my sons would have loved them, and they do fit family culture a bit. Women would register their patterns at stores, and an aunt might give you a single setting as a wedding present. That didn't happen to us, but it was still in collective memory among even young women then. I doubt many 20-year olds think this way now. People marry later, move more often, eat out more, and eat far less formally at home. The intuition has changed.
There may be American subcultures, particularly among the wealthy, where china patterns and crystal remain an everyday conversation, and if so, I would like to hear about them. Many of us acquired what knowledge we have by working in finer restaurants. Kyle's girlfriend was born in England, so she may have different customs and mindset. They will all recognise some of the elements of formal dining customs for a few generations yet. Words, designs, and customs are still known and understood long after they have gone out of use or fashion.