I once wrote that Melancholia provides the only possible answer for what to do when you know for sure you’re going to die and yet you still have agency up until that moment. In that situation, where every action would be meaningless, there are no good options — indulging in one last pleasure would be hollow, pretending everything is normal would be pathetic, etc. The only possible choice is to make a gesture that is consciously meaningless, like the building of the shelter at the end of Melancholia.
In many ways, adult birthdays share a similar structure with the apocalypse of Melancholia. They are inevitable and utterly meaningless, and yet we are forced to respond in some way. Why not, then, take a parallel strategy by consciously choosing to do something just as contrived and silly as the convention of birthday observance is after the age of 21? Why not — as The Girlfriend suggested and as became inevitable the second the idea left her lips — celebrate my birthday this evening by going to Olive Garden?