TV psychics are edited.
All mediums misinterpret some information. What you have seen on TV has been edited for time to remove all the times someone says, "No, I don't understand that."
"They wouldn't know that."
People in Spirit do know what's going on in our lives after they have passed. It is a common misunderstanding that when they refer to things currently happening in our lives that the medium is psychically reading the client instead of getting information from the Person in Spirit.
"They wouldn't know each other."
People who did not know each other in physical life can come through together in a reading. If they both knew you, they can know each other now.
"They wouldn't come through for me / I didn't know them / I wasn't close to them."
If you know enough about someone to recognize information about them, they can come through in a reading, including people who passed before you were born.
"It's too long or too soon since their passing for them to come through."
How long ago they passed does not matter at all.
"Everything you're saying is for someone I know who is still living."
When this happens in a group event, it's to get me to a specific person in the group. When this happens one-on-one the Person in Spirit is more closely connected to the living person than to the client (your friend's dad, for example, instead of your own father).