What is it like having siblings?

my older sister is a strong female presence in our lives. she's always available to listen to my brother and i complain, and (only when asked) she provides some advice. my little brother is a trouble maker, always competing with me. we are best friends but don't tell him i said so. having siblings is like having alter ego's in the flesh. we get along (most of the time) but having a sibling means having a best friend.