I am recalling here a sequence from the film Jaane Tu Ya Jaane Na. Prateek, the brother, asks his sister Genelia, if she can recall any of his childhood friends. Genelia thinks for a while and then says, 'No'. Prateek says,'There was none. You were my only friend, and I never felt the need for another one.'
Few things don't change. A sister's love for her brother is one such thing. A sister is a little bit of one's childhood that is never lost. A sister is her brother's first playmate. Older sibling is the first teacher. Siblings may not meet frequently, and may have their own world, but they can be the best friends.
In a brother-sister relationship, there is clear understanding that distance is as important as closeness is, and space is as important as togetherness is.
Quarrels are a natural part of a brother-sister relationship; love resurfaces even after bitter quarrels. A moderate amount of sibling conflict plays a potentially beneficial role in their social interaction with peers.
Siblings generally know each other very well. This intimacy can be of use in either way. In many situations, siblings understand each other's problems and dilemmas better than even parents can.
Long live brother-sister relationship.