If God is everything, then he is both one and many. You are not God, you are that aspect of God which is many. God, as it is said in Sufism, is the source of both unity and diversity.

Our connection to the "One" is like an umbilical cord, which people connect to through meditation etc. Therefore you do not have access to the umbilical cord of another, and perceive your mind as your personal private mind, even if it is known to the One and is a part of the mind of the All.

At least, we do not have access to the umbilical cords of others before returning to the one through "retracting into the umbilical cord" at the moment of death, at which point it is commonly reported that people suddenly lose their feeling of ego and feel at one with all.

None of your thoughts and actions are private. They never have been. None of your thoughts and actions are "yours".

They are the thoughts and actions of The All, through you.