For example: A person might see something someone else is doing or heard what that person and what that person did or said, they notice that's what they do or say all the time. Or if someone liked the same basketball team as you and you ask them, " What is their favorite team?" and they say the team that you like, that's something y'all have in common. The only way you can uncover what you and some else like, you have to ask. That is basically it.
Good question btw. Hopefully, that answers your question!!
