A birthday card can arrive on time while its words belong to an earlier understanding of you.

People update slowly. Someone can be entirely reliable about the date and still be writing to the person you were at twenty-two, with the same joke about your job and the same assumption about what you want. The reliability is real affection; the outdatedness is just what happens when contact thins to once a year. Both things are true at the same time, which is why the card can feel warm and slightly lonely together.

You can let it be, or you can give them something to update with. Send back more than a thank you: one paragraph about who you are now.