Thoughts from a desert isle...
I used to think it was a given that if you cared for a person, you would go out of your way to make that person feel special in little ways. I thought everyone thought like this. With the exception of course of crappy, criminal-type people. I was wrong.
It just doesn't occur to some people to do that sort of thing. Either they were not brought up in families that made a big deal about each other, or else they are actually oblivious to the fact that people around them have gone out of their way to do something to please them and do not think to do the same in return.
Oh they love you, they don't want to see you hurt or poor or sick or in dire straits. They'll help you out if you ask for it. But if you're far away and lonely, they won't think to send photos or keep you up to date as if you were close. They don't care if you do anything for their birthday or not, and expect you not to care either. Birthday and Christmas gifts, if they get you any, are symbolic tokens only because they really have no idea what you like, because they don't make a point of remembering when you exclaim over something.
They aren't mean-hearted, they aren't cheap or miserly, it's not like they don't appreciate you, they just don't see the point in getting excited over nothing.
For someone who delights in doing little things for someone they care about, it's hard to understand someone who doesn't. In fact, more often, we might tend to think that that someone doesn't care at all. Even when it isn't true.
Disappointment comes in waves, like the ones crashing against the shoreline of my island, and then it goes out with the tide.