I think pretty much every nation has its stereotypes that the world knows them for. And movies tend to emphasize these stereotypes a lot, some are even completely based on them. Germans are known to work like clocks, machines, always being absolutely perfectly on time, working really really hard, being super smart, very serious, not having humour, being dried up and boring, sausage and sauerkraut eating, bear drinking and everybody always running around in the costumes like in the movie about "Heidi". But thats not true!!!
In Germany (or also in many many other countries) the Americans are known for being completely arrogant and not exepting that they dont OWN the world, being super obese and only eating at McDonalds and drinkin coke, being super dumb and hipocrits, thinking to be able to get out of every uncomfortable situation, either with money or because theyre the "greatest nation on the planet". But thats not true either!!!
There are fat people, dumb people, hipocritical and arrogant people, that only eat McDonalds and drink coke all over the world. Just like the bear drinking, sausage eating smart, punctual, dried up people without humour that Germany is known for.
So the only thing I can advise you to do is....Stop believing everything the media tells you and if you really want to know what Germans are like, buy a plane ticket and travel around Germany and you will see that just like in the States, in Germany as well every region has its own special sense of humour, their own way of living, their own accent and their own stereotype that they are known for in Germany. Oh and you will find out, I know shocking but true, that Bavaria doesnt automatically mean Germany.
I find it quite sad, that some people live with these stereotypes all their life not wanting to change their point-of-view because their stuck in their own circle of lies around those prejudices. So if you really want to know what people in other countries are like, travel there and make your own experiences that you can live with, because even if you find out that some people perfectly fit the stereotype or the impression you had before, Im very very sure you will also find a great number of people that DO NOT fit those types at all. I can give you one example:
I am German (my parents are german, my grandparetns are german and my whole family goes many generations back of being absolutely GERMAN), I was born in Tuebingen - a city close to Stuttgart in the South of Germany - but I grew up in Hamburg - in the North of Germany and my absolute favourite city in Europe - . I left home with 16, going off to Boarding School in the UK, and now spending time in Spain to learn Spanish. So far that already proves that some of the typical things the world 'knows' about Germany dont apply to EVERYONE. NORMALLY people dont live in the south and north of Germany, because the south doesnt like the norht and the other way round, WRONG! then people think that we dont like the British, WRONG! Would my whole family go to the UK to study if we didnt like the British?? I dont think so. Maybe I am a special case, but although I have the typical german appearance (tall, blonde, blue eyes) I am the only one in my family with that combination. Also all my foreign friends tell me i have humour, Im known to generally not be on time and most importantly I absolute HATE beer. Hows that???
Oh and just to make sure. I did not make any of that up. So maybe I could make it clear enough to inspire you to maybe travel around the world yourself. You will always make bad experiences, but the good ones you will keep for the rest of your life. TRUST ME!