Holidays when you get home are extra awesome. Everyone is excited to see you. Since you haven't been physically present it's unlikely that you've managed to make anyone upset enough to be put out with you during your visit. After all, it will probably be months until they see you again. You are in a pretty good mood as well. You haven't seen these people, otherwise known as your family, in a long time and let's be honest, having people excited to see you makes everyone feel a bit more fantastic. For me, I find that my mom and I get along amazingly from a distance but more than a week in the same house and we are at each others throats.
Holidays when you can't go home aren't quite as much fun. There are a couple possibilities here. The less craptastic is finds you with friends, a significant other, or someone else's family. Not horrible, but it's not the same as being home. The other two possibilities are substantially less fun - and sort of a toss up of suckage: either you are stuck at work or you are by yourself. In my experience, being alone on a holiday tends to be a choice - sometimes I just can handle being with another group, especially when I was really hoping to make it home. Working on a holiday sucks whether you are close to home or not.
You get used to missing things when you live "too far" away. Going home is expensive or time consuming, so you tend to skip graduations, baptisms, those random weekends when the family just all seems to get together. BUT you call for all those occasions. You send cards, flowers, gifts, whatever is appropriate. People come to expect you not to be able to make it. You start only getting invitations to the big things. The family camping trip or trip to Aunt Sue's isn't mentioned until after the fact. I admit, hearing those stories sort of hurts. It's always weird to think of people having a life without you present. I don't resent it, just sad I'm missing out on the memories, the time together, the closeness.
When it really sucks is when something major happens. You sister has a kid and you just can't get the time off or maybe the plane tickets are way out of your budget. A family member gets married and it's high volume season at work, so taking off the three days a trip home requires just isn't an option. A family member is sick, and you don't make it in time to be there for them or the rest of the family. Lately I've been in the really sucks bracket. It's never been so hard to not be home. As usual, I find myself being unbelievably jealous that they all get to be together and draw comfort from one another while I'm solo in the apartment trying to keep myself together. Again, I don't resent them for this, but I just really wish I could be there too. Not just for me, but for them as well. In time of crisis, families come together, and I can't do that, which hurts so much.
I feel silly for saying it, but I'm a very homesick 30-year-old.