Too much of anything can kill you

When I was 10, our teacher made a bold claim..."An unlimited amount of anything can kill you".
Some of my classmates seemed astounded.
"What about food?" they asked.
She replied, "If you eat too much food, you'll become fat and have many health problems, eventually your heart will stop and you'll die"
"What about money?" they asked.
She replied, "Too much money could build up in your house and take up all the space, you'll suffocate and die."
... on and on this went, with each suggestion ending in a road to death, until I raised my hand...
"What about Birthdays? Could you die from an unlimited amount of Birthdays?"
She paused for a moment, her jaw agape... defeat slowly setting in her eyes.

I can't think of a punchline. Sorry, I'm drunk.