The idea of being present in the moment always reminds me of the following quote:
You cannot step twice into the same rivers; for fresh waters are ever flowing in upon you.
… which I thought was Buddhist or Taoist, but it’s from Heraclitus (535 – 475 BC), a revered pre-Socratic Greek philosopher-mystic, said to have taught in aphorisms similar to Zen koans. He is credited with originating the idea of the Logos (Word) as an underlying order and oneness in the Universe, and also a yin-yang balance inherent in opposition.
Realize deeply that the present moment is all you ever have.
Eckart Tolle, author of The Power of Now: