There are other examples in the birthday thread where people say that their therapists don't say "happy birthday" to them even when they know. You could say that is a boundary, but jeepers how much effort does it take to wish someone a happy birthday? And why in the world would someone do that to another? It's just not human.

I don't expect therapists to remember birthdays or do anything about it if they do know, but a verbal gesture is hardly asking for much.