At first I was a bit reluctant to tell my tale of pain, but here goes.
In late 2009 I asked the D&D gaming group that I DM if we could take a brief break and have one of the players run a game of Classic Traveller for me. You see, back on Christmas day of 1979 I got a copy of Traveller. That was my start with RPGs, so I thought it would be great to play a Traveller game in honor of my 30th year of gaming.
My roommate wanted to run the game, and I gave him whatever help he needed to get the game going. We pre-rolled the characters, made a nice character sheet for everyone, and even prepared a briefing paper to get everyone into the feel of a classic 70s era space opera style game.
The problem was that three players just did not understand the style of game we were playing. One could not understand that the game was not a futuristic view of the universe viewed from 2009, but a view of the future from 1979. We tried telling her that she should look at the Buck Rogers series or the Flash Gordon movie (both of which she is old enough to have seen first run), but she just couldn't get it. She thought her comm unit should be as small and versatile as her cell phone, for example, instead of being more like an old Star Trek communicator. That is just one example.
A younger player also had tech issues. She could not grasp that there was no galaxy-spanning faster than light communications system. Instead, Traveller has a data transfer system more like the Pony Express and sailing ships. She kept expressing frustration when she was told she could not send an email from one star system to another and expect an answer within a day or less.
Finally we had one player who had been messed up by someone who ran a pseudo-MegaTraveller game in a very messed up fashion. The player came to our game with a strange and distorted vision of what is Traveller. We tried to explain that what happened in the other game was not what Traveller is about, and that he should listen to the background for this game. He really did not pay attention, did not read the info given to him, and just did not get the theme of the campaign. We told him that he could have equipment found in the Traveller books (all of the LBBs). He wanted a device that was available in his other game. When he was told that it was not available in the game he kept bugging the Ref to let him build and/or invent the device (an overpowered scanning/vision enhancement device). Both the Ref and I finally had to tell him that if he can find the device in the books we gave him to read he could get it, but if it is not there it is just not available in this universe. He still wanted to invent it, and that is when the Ref had to tell him no, it is not possible.
After we had several sessions, and people working hard to not revert to their usual D&D Hack & Slash style, the adventure came to a close. I then packed all my Traveller books into a box, dated it, and put a label on it to NEVER play it again with this group.