Well, I don't think this is a choice, so probably can't be being unreasonable about it. But is it unreasonable to think that women/girls with sisters always have that constant security from childhood and never really become super close to other friends? I don't have a sister, so I don't know, and the only women I know with sisters are very friendly and lovely people, but somehow we never get beyond a certain level of intimacy. Or am I a loon?