I really don't think it is a big deal. A one year old isn't really going to notice, so honestly it is all about the adults anyway. If your inclination is not to be miffed by their absence, then don't be. Why would you go out of your way to feel hurt??? All your precious little child needs is their parents (yes, even on their 1st birthday), the rest of it (whilst nice for you, the parents) really isn't a big deal.