The body and mind are continually changing, and are, in fact, only names of series of changeful phenomena, like rivers whose waters are in a constant state of flux, yet presenting the appearance of unbroken streams. Every particle in this body is continually changing; no one has the same body for many minutes together, and yet we think of it as the same body.
Swami Vivekananda (2015). “Jnana Yoga: The Yoga of Knowledge”, p.25, Advaita Ashrama