Also, oxygen. (Edit: "You are the only common denominator in all of your failed relationships." is misleading, hiding all the other common elements.)
What we want to find is the denominator common to all of your failed relationships, but absent from the successful relationships that other people have (the presumed question being "why do all my relationships fail, but Alice, Bob, Carol, etc. have successful ones?"). Oxygen doesn't fit the bill.
Another month has passed and here is a new rationality quotes thread. The usual rules are: