To know the score means to know the facts about life and its difficulties, and in this context the speaker is saying she never got involved with people who were naive to know about life and its difficulties
Context: "I never got involved with anyone who was married or too young or too naive to know about life and its difficulties." Claim: "I never got involved with anyone who was married or too young or too naive to know the score."
Considering the context, is the claim true, false, or unknown?