One example, when invited to a co-workers wedding, the expectations of what was the norm for invited guests and what I was prepared to do were so totally different that I found the invitation to be not a friendly gesture but an onerous obligation. I am sure that that was not the intention of the invitation, but it was definitely too onerous for my sensibilities.
The second example was talking about the expectations one family wanted from their child's school. Without going into deep details, this family expected the school to be able to do much more than is expected by an American public school. This family felt deeply hurt that the school was not able to fascilitate their needs and felt that the taxes they were paying were a waste of money since they were not getting what they were paying for.
As I had conversations with these two people, I realised that they were indeed so different from me that in fact culture is not just traditions or a way of life that is different, but an inherent different way of looking at everything in life. Family values, social values, even moral issues, are somehow so deep that when we think that differences do not matter, we are really just hiding the fact that we really are very different underneath after all and the differences do matter much more than we thought.