Cultural differences

Most of the time, at least from my experience, cultural differences are perceived as a value. Something good. It's good to interact with another cultures, it's good to experience it and to be tolerant. To accept the culture (not taking as yours but accept) and live in peace. Together. And I thought the same.
Culture (among others) affects your personal hierarchy, makes your values, your personal judgments, of course your behaviour.
If for somebody it is normal to have a nap after lunch and for you not, that's fine. The one can have a nap, you don't have to. When somebody is used to go out for eating and you're not, that's ok. You can try it (of course if you can afford it) – maybe you'll like it, maybe you won't. If you will, you can take this cultural difference into your life, change your habits a bit, and that's fine.
But the problem is when cultural differences go deeper, into your hierarchy of values, and affects your daily life. Then they may destroy your relations with people around and you won't even notice it. And when you realize it, it might be too late to live your life like you used to live it. Because you haven't been aware enough to protect yourself since the very beginning. Aware of cultural differences which go very deep in your perception of the world, of proper behaviour, of division between that what is good and what is bad.
And it seems that my view to cultural differences changed.