Studying German-speaking cultures has demonstrated that German-speaking people can come from vastly different cultures, from Switzerland to Austria to North versus South Germany to the West versus the East. Just as not all Americans are alike, not all German speaking people are the same. I have also learned not to make assumptions about German behavior. Just as Germans ought not to assume that Americans do not make make good friends just because they don't invest a lot of time in getting to know every person they are friendly toward, Americans ought not to assume that Germans are unfriendly just because it takes a long time for them to feel comfortable with someone. Because my  grandfather came to the United States from Germany but refused to talk about his homeland, studying about German-speaking cultures has broadened my understanding of the sort of culture he came from despite the fact that he did not feel comfortable talking about. It has also helped explain some of his personal traits and behavior, which retained their German character.