There Are Three Types of "I"

And there is only one True "I". 

1. No-Self, False "I".

This is the "I" we normally refer to ourselves as. This is the physically visible, existing "I" we call ourselves in the human realm. This is the false "I" that goes through the continuous rebirth cycle of samsara because this "I" attaches itself to an ego. The stronger the ego, the stronger the karma that prevents one from discovering the true "I" that has resided within oneself all along. 

2. Gap-I, In-Transit "I".

Gap-I has a lifespan of up to forty-nine human realm days. Gap-I is invisible and without a physical body, but it can see, move around without any physical impediments like walls, and move fast, reaching an infinite distance in a fraction of a second. It is constantly, often desperately, seeking a next life and is reborn during this limited time. Karma is the main determinant of what form of life it is going to transit into.

3. True-I

Then, there is the True-I that we always had, have, and will always have—the one "I," ourselves. This "I" never dies or is reborn. This is the true "I" that is described in the Heart Sutra as an entity that is "neither born nor destroyed; neither dirty nor pure; neither increasing nor decreasing" 불생불멸 불구부정 부증불감 不生不滅 不垢不淨 不增不減.