"THE TWO MOST IMPORTANT DAYS IN YOUR LIFE ARE THE DAY YOU WERE BORN AND THE DAY YOU FIND OUT WHY."
Mark Twain
Plato (428-347 BC) said the meaning of life is the pursuit of knowledge. We are all born with all knowledge inside us but we have to recall ir or rediscover it, which is a concept called anamnesis.
Plato wrote his most influential work in 375 The Republic.