There might be a trainable skill of noticing high-leverage facts. For example, a friend of mine claims that a modest weekly investment in keeping up with soccer allows him to 'have a good conversation with any man'. In particular example, a basic knowledge of the proceedings of a FIFA World Cup while it is taking place is extremely cheap but might be extremely high leverage depending on where one lives and the demographic distribution of one's interlocutors.

Similarly 'current affairs' (legislation, policy, political manoeuvrings, disasters, humorous stories, etc.)

Also, I encourage this kind of experimentation post.