Tennis players never say a player score is "zero" or "nothing" when that player hasn't scored a point in a game. They say "love" instead. No one knows for sure how this word came into use, but it probably happened like this:

Centuries ago, French tennis players drew zeroes on their scoresheets that were oval in shape, and looked like eggs. So the zero became known as loeuf,which means"egg" in French. This French word sounds very much like"love", so players in England began to call the zero "love", and that word has been used ever since.