Know a little bit about a lot of things. Have some knowledge in your head on as many subjects as possible. That way whenever something is overheard or read or seen somewhere instead of having to say ” I have no knowledge about that” or even worse ” I haven’t a clue about what you are talking about”, you will be able to say “that is interesting, now I know more about that subject” or you will be knowledgeable enough to be included in the conversation as an equal.
Learning never stops. Don’t limit yourself.