I have always had this theory to keep expectations low or to be precise, to zero.
This way, you can avoid hurting yourself..
I know expecting is a way of self torture.. When you expect something out of a person and it isn't fulfilled, you feel bad. so the easy way out is, dont expect. If the other person does something for you going out of his/her way, take it as a bonus.
Few days back, I was having a conversation with this friend of mine which got me into thinking mode (yeah, I know in a long time though).
She says, you may pretend to not expect, but it is human to expect and if you say, you don't expect, it is not being modest, rather you are escaping the truth.
I kept thinking over it and then finally reached the conclusion, she is right.
Any person who is close to you, may it be your parents, siblings, best friends, or a special one, you tend to do things for them even if you have to trouble yourself or go through terrible inconvenience, you do, it is because you want to.
And you want them to do things for you the same way. You want them to be there for you in the moments of distress. This may and may not be in return of what you do for them. It hurts you if they are unable to make it on time for you.
You may ignore it for once, but somethings you are incapable of letting go. At times, you start listing down the times you have been there for them and things you did for them and the times they weren't there for you.
You may not convey it to them, you may conceal that you are feeling bad but doesn't it get suffocating at times? It does. Blood relations kept aside, it starts driving you away from them. And if you convey it to them, this might result in a disagreement and sometimes frictions.

Expectations are confusing in themselves.

Deep down, we all have expectations. We just learn to suppress them. For once this may be convenient. But in the end, they bind you with your loved ones.