My Best Friend

Everyone has his own defination of the best friend. The best friend don't have to be the one that experience some big events together with you. In my opinion, a good friendship should mean a long time of the relationship in which there is a tacit agreement between two people even though they don't contact each other often. My best friend is such a person.
We were born, and grew up in the same apartment. My family was living on the 3rd floor, and his family was living on the 2nd floor. We often played together in our childhoods, but we didn't really understand what the friendship is. We were seperated when I was ten years old, and his family moved into new apartment. However, we had never stopped keeping in touch with each other because we lived in the same city.
Every weekend, we went to play pingpong together, and he always invited me to his family. His parents regard me as a member of his family. We didn't go to the same middle school and high school; however, we always spent most of our to doing something together during the vacations. Sometimes, we could understand each other just by a look.
Nowadays, we are studying in two colleges of two countries, but we are still in touch with each other. I find out something interesting at this moment: Today the person who I described is the same one with that my primary school teacher asked me to write about my best friend in the writing class.