While reading something for a few minutes, when you are immersed in it, i.e. when the I sense has dissolved, just inquire who is reading and see if you notice a presence*. There has to be somebody/something that is reading in the absence of the I sense.

While watching TV for a few minutes, when you are immersed in it, i.e. when the I sense has dissolved, just inquire who is watching/listening and see if you notice a presence*. There has to be somebody/something that is watching/listening in the absence of the I sense.

*Presence word is a pointer. Awareness word is more accurate. When I sense has gone and there is no false identification, you are pure awareness and awareness can recognise itself.