So loudly in fact that, at some level, you feel everyone else can hear it, and they're just refusing to pay attention to it. "Surely," you're saying to yourself, "they must realise that I feel left out and abandoned and banished, like some pariah pounding her little fists at the castle walls begging to be let in!" Your distress is so howlingly clear to you, that you can't believe your family are not aware of it.
But the truth is, they're not. You conceal it very well, with your successful career, wide circle of friends and apparently totally self-sufficient lifestyle. Indeed, they're probably frightened of asking you in case you were to sneer and say: "Family holiday? You want me to come? Surrounded by screaming kids? Making boring conversation to you lot? I'd rather spend a week in Gaza, thanks."
So how are they to know you'd like to be invited? Well, you have to tell them. Now this is difficult, of course, because you're frightened that once you allow this vulnerable self to speak it'll start shrieking and cause the neighbours to lean out of the windows and call the police. You've kept silent about your needs for so long that it's all bottled up and raging. A tiger in a cage is far more dangerous than a tiger you might meet just strolling along the street.
Far better, if you can, to say, casually, in the same tones as Pooh might ask what's for tea in the desperate hopes there's honey: "I suppose there isn't a room spare for me to come and visit, is there? I'd so love to join you." Or: "How would you feel if I popped down and checked in to a nearby B&B for a few days? It'd be lovely to be with you all. I don't see nearly enough of you and I know it's all my fault."
Who knows, maybe while you're feeling unwanted by them, they're also feeling unwanted by you -- and they'd be immensely comforted and flattered to know that you wanted to spend time with them.
Drop some hints
My wife and I have experienced this sort of thing in a much bigger way. Her parents tend to organise "rich-club" get-togethers with the better-off grown-up children and then expect all members of the extended family to cross the Atlantic on their terms, even if this is too inconvenient or expensive for some of us. Anyone who can flash their money around and subsidise her parents gets extra brownie points.
In this situation, some decades back, having children was a disadvantage -- the reverse of your situation. All very hurtful, but it's been no good complaining, so we refuse now to play the game, although we still see my wife's parents, usually when they visit us, and are on generally good terms.
I suggest you hide your disappointment and say how lovely it is that they're all off together. But drop a hint that you've got a spare few days and that you'd like to pop over to see them. When you get there, say that you've been very busy with your career etc, but next time you'd also love to join in for a few days. This gives everyone a chance to take a strong hint.
If they don't take the hint, you may be in for a much worse problem, similar to the one that my wife and I have had. But look on the bright side for now, and give it a go.
> John, by email
It's time to confess
Being the one without the children can make you feel less interesting and important than your sibling who has supplied the grandchildren. I was the childless achiever in my extended family and felt the same. It may be that you have overcompensated by emphasising your fabulous exciting life, and everyone is actually a bit afraid of you.
I would just 'fess up, be really pathetic and beg to be invited, offer to babysit, the whole nine yards. I'm sure they'll happily include you.
> Sue, By email
I'm sure your parents didn't mean to hurt you by excluding you. They may, as you suggest, have thought you were too busy -- or felt that your brother and his family couldn't afford a really nice holiday.
There are several ways you could approach the problem. If your relationship with your parents is really open, you could simply say: "You know, that sounds such fun -- I'd love to come too! Is there room for one more? I'd pay my way, of course!"
Or, if confronting them directly makes you feel uncomfortable, perhaps you could say to your brother: "I'd love to join you all -- do you think you could suggest it to the parents?"
If neither of those approaches is one that you feel happy with, then I think you'll just have to book yourself a really special holiday this year, and forget about what a nice time they are all having. Then (if it has been a success -- it may not, of course!) you could liaise with brother and/or parents to arrange another family holiday in future.