Sorry, excuse me, please could I possibly...
You may or may not have heard a stereotype that British people are very polite, sometimes too polite. That they always apologise for everything, even things that don't necessarily need to be apologised for, and they can spend a long time doing so. For me it is normal to do this. I am a very polite person and will always apologise for walking into someone or getting in someone's way in the street and I normally also expect that the other person involved will apologise too.
Before I moved to Germany I was told that Europeans are more direct and not as unnecessarily polite as us Brits. The thought didn't bother me because I did not really see myself as overly polite until I moved over here. Here there is no need for an apology when you stand on someone's toe or try to walk in the same direction as another person. I am constantly surprised that people do not apologise to me when they have stood on my foot, hit me over the head with their bag or just walked straight into me because I am so used to it. One of my colleagues over here explained to me that most Germans feel no need to apologise as both people involved should know that it was an accident. It was not a deliberate or intended action and therefore needs no apology.
Of course this now makes sense to me. When you're in a rush or are very busy, why waste time apologising over and over again to someone who already knows that you did not mean something? I still find it very strange though and often find myself muttering a quiet "sorry" when something like this occurs. I then still find it strange when I don't receive an apology back. I hope that I will get more used to this as sometimes it can leave me feeling quite annoyed or upset and have to always remind myself of the fact that an apology has not been said because it is not needed! My over-politeness also comes across in conversations where I may apologise for disagreeing with an opinion or something someone has said, and they look at me like I'm crazy because I have apologised, or ask me why on earth I am apologising for something. It's a hard habit to break but hopefully with time I will get used to this, although it will probably be just in time for me to return to the UK where I will aggravate other Brits by not apologising again for everything!