There are 2 versions of the scenario for conversation:
A person suddenly changes his natural way of talking to one characteristic of a poet, a philosopher, and a journalist all rolled into one. It becomes easy for him to talk on the most complicated and interesting subjects even if he has never thought about them before. If you’re lucky enough, an ordinary person will turn into a comedian.
A reasonable and knowledgeable person turns into a stupid sheep that has an extremely poor vocabulary. If it applies to you, try to limit attempts to impress another person.