Expectations and meeting them

Friends and expectations. Should one go with the other or do they never go together?
Should we expect more because he or she is a friend or less because we understand and vice-versa?
I am confused. Because that is what it has boiled down to, expectations and then when they are not met, disappointments.
You expect friends to remember birthdays, because you keep a tab on theirs too and memorise theirs and their kids bdays too.
Then when you go on trips, you expect to go in a group and when that dosen't materialise, because your husband works, or because the others are going on another trip the next day, you feel left-out. You feel more so when noone remembers to ask you to tag along with kids(more so because you have always been extra careful and sensitive and asked the wives and the kids to join in when the husbands aren't around). Again disappointment!
This is how I see the whole picture, you aren't a S or an A, but a Mrs.K and when the male counterpart isn't around, you just don't exist!
So friends are all good, when you move as a group, but the minute you are just a S, you have few to fall back on.
This is what I meant in my earlier blog on friends and the lack of good friends, friends who like me for what I am and not because I am someone's wife.
Not to forget the lesson learnt from all these -- the lesser you expect, the lesser disappointed you feel. And this goes for all relations, not just friends.