Culture ("how we differ")

Who you are (and what you like, what you're used to) drives how you behave.

So people will act differently in different parts of the world, a country, a city, even depending on what family members or friends expect of them.  It may seem quite normal to them.

You may think you're in charge of your behaviour, but in truth your emotions and experience are.  Plus who you want to impress, or are scared of.  (Thankfully, that lessens with age).

In summary, what you see as rude may just be assertive; what you see as exceptionally kind may be taken as merely adequate.  Know the expectations of road users around you ... and go generously.