You can never be certain of living long enough to take another breath. The first breath catch us off guard. Our wandering attention is surprised by the notice of the breath. The freshness of the air passing into the nose. It warms and fills the chest as it descends. The sensations prickle with energy and varying levels of clarity.
Galileo and the famous Japanese haiku poet Matsuo Basho where contemporaries inhabiting different global regions, breathing the same air but likely didn't meet. The second breath announces its familiarity. It's relaxed in its repetitiveness. We sink deeper into the moment of breathing. The body isn't inactive. Tingling, heat, cold, pressure, sounds, thoughts, and feelings appear in the space of awareness. The feet receive sensations where they contacts the floor. The butt receives sensations where it contacts the chair. There is both a metaphysical and physical taste to the breath.
Each breath does not leave any residue for the next. The third breath is settled in the moment. Breath just breathes.