Just reminded me of the Birthday Wish in the game. For what it's worth!
Oh this is something that haunted me for a solid year when I had my town.
If you don't want to end up losing your mind, DON'T tell them your Birthday Wish, I implore you!
I made the mistake of telling them, I rushed it and typed in 'Birthday Cake', thinking that's how I'd get the actual in game item, but no. It started a year long downward spiral into complete and utter despair.
Every day, all ten villagers would bring up the Birthday Wish. "Did you get your birthday cake?" And it was more than once each per day. Up to thirty times a day I'd be asked about it, and I googled how to stop them asking, and apart from time travelling to your next birthday and opting to 'keep it a secret' (Birthday Wish), there is no way to stop them.
I got to a point where I booted villagers out. Then when I'd amiibo a new one in to replace each villager infected by the Birthday Wish curse, I'd talk to them, and apart from the usual first time greeting and pleasantries, the first thing they'd say to me was, "I'm so glad I was able to be part of helping with your BIRTHDAY WISH!" (Or words to that effect.)
O_O
Helping?
You JUST met me!
Alas, new villagers inherit the 'Birthday Wish' curse.
So.. if you don't want to end up huddled in a corner, covered in peanut butter, reading 'The Cat in the Hat' whilst mumbling incessantly 'Bbbbbirthday Wwwwish', I suggest you
keep it a secret!
I hope this helps someone.