You would call me a fool and say the answer to the question is taste enhancement but that is not the origin of the lemon besides the fish. Before people thought about consequences all the time, not so anymore because our security is always handled by someone else. Earlier in time, about six hundred years ago, people weren’t protected by others so they had to do it themselves. Some people swallowed bones of the fish by accident and it was a myth that lemon juice would help you remove the bone. At it was true, sucking on a lemon causes the throat muscles to contort, therefor helping to dislodge any stuck bone.