In the practice of human communication, most of you need to relate to a wide variety of people and discuss many different topics. However, to do this well you must adjust to the different people and have some knowledge of, or at least curiosity about, their topics.
I have observed that adults who are "specialists" liked to talk mainly about their pet topics and became uncomfortable when the conversation shifted to a toic they didn't know or care about. For example, some men I've known have only a few comfortable topics, such as guns, cars, and sports. Some business persons like the focus to be mainly on commerce and shop-talk. Some women like to talk about their children, fashion, and social life, but not about "guy topics." And so it often is: Conversers often favor topics related to their gender or occupation.
Here's what I've found: Being able - or at least willing - to talk about many different topics gives one a sense of freedom and confidence in everyday life. You can relate easily to different people instead of trying to avoid certain ones.
Certainly, you can't know everything, and you don't have to. But it's necessary to be aware of what's happening in the world, nation, and your community, and to be well informed by learning from both smart people and various media.
When you're in the company of people with special knowledge you don't have, you can assume the complementary role of learner by asking a few questions and listening carefully.
Great conversationalists are more like a Swiss Army Knife than a single blade. They are able to use different skills to perform many functions. That's what you can do as a general practitioner of conversation.
