This is my list....so consider it the topics that an American would observe and note about Germans and Christmas. You might have gotten a totally different list from a German.
First, while Germans won't admit it.....the shopping frenzy you see in the US....has moved over into Germany and taken root. It may not be as big a frenzy....but Germans are working on it.
Second, Christmas markets....always in the downtown region of cities....is probably half the fun of German Christmas opportunities. Of course, this revolves around great food, great beverages, and a robust atmosphere.
Third, Christmas trees don't typically get put up until after the 15th of December. So don't get nervous if you don't yet see a tree up.
Fourth, alcohol of various types....fit into the German tradition. If you have a 'dry' feeling, it's best to keep it to yourself. And yes, Germans are probably a bit more 'lit-up' than they normally would be.
Fifth, Saturdays are the worst shopping day of the week to be out and about for the next four weeks. Forget about finding parking spots unless you get out at 8AM.
Sixth, various German cookies and cakes are being made as we speak. Germans will try to squeeze thousands of extra calories into you prior to the Christmas meal. It's best to just accept it and enjoy.
Seventh, for Christmas-theme movies....don't be counting on a number of German four-star choices to pick from. The vast majority are two-star picks and you will begin to realize that after a while.
Eighth, you need to plan every hour out once you within seventy-two hours of Christmas day. Remember, most shops close early on the 24th....usually between noon and 2PM. The 26th is a German holiday as well...so don't plan on any shopping events. In this three day period of holidays....there's probably around 15k calories of food and beverage to be consumed by the typical German male per day.
Ninth, the odds of snow on Christmas? Actually, unless you live in the Alps....you'd best plan on no snow for Christmas. Statistically, it's against the odds to have snow falling on that day.
Tenth, yes....there are Germans who would prefer to climb on board a jet and fly off for the Christmas holidays in Spain or Italy. It's a small number....but some folks would rather avoid the whole Christmas 'rush' or the stress involved.