Nour, I don't know if this is true) I learned a lot from my best friends.

But when I meet somebody different (or notice some difference in a person othervise similar) - sometimes I intentionaly try to understand it and learn from it 'just because he/she is different'.

If you are talking about languages, then I think when you put yourself in a situation in which you MUST speak a different language than your native one then you will learn it, you kinda force yourself to speak so you manage to learn this language. :)