Statistically speaking, that may be a probability, but when it comes to 100% positivity wouldn't you need 367 people to be sure of overlapping birthdays?
Non sequitur - a statement (such as a response) that does not follow logically from or is not clearly related to anything previously said We were talking about the new restaurant when she threw in some non sequitur about her dog.
Do you find it difficult to avoid rising to the bait?