The number of individual beings which could be standing here in your place vastly outnumbers all of the grains of sand, on all of the beaches, in the entire world. You're the inheritor of a genetic legacy which stretches back 3.8 billion years through the eons, and which has circled the center of our galaxy about 20 times.
You're the endpoint of billions of generations of birth, competitions, wars, and deaths; the only possible sequence of hereditary combinations that can possibly result in you. Your forbears have survived arguably the single greatest ecological catastrophe ever to hit the planet; when the earliest plants started poisoning the atmosphere with oxygen. Yet, your ancestors learned to use this poisonous gas to produce energy in a way that had never been attempted before; an evolutionary triumph which paved the way for the first multicellular life. Your genetic line has survived floods, freezes, and meteor impacts from the skies themselves, preserving this single genetic line through the eons to lead ultimately to you. This is a legacy you share with every living thing on earth, from the largest creature ever to have lived; the blue whale; to the lowliest prion. You share this legacy with the blades of grass between your toes and the trees that give you shade. You are a thread in a huge, amazing, incredibly diverse tapestry of living things; some of whom have clawed their way out of the seas to survive on land, some of whom remained in the ocean, and a few of whom stood on land for a few million years, ultimately said "well, screw this" and marched back into the sea.
Once we add cosmology into the mix, not only does this legacy stretch to everything living, but to the non-living as well. You share your origins with the stars and planets, the asteroids which hang in space, all the way down to the loneliest hydrogen atom in deep space. All the parts that make you stretch back through the eons and have borne witness to the very birth of the universe. They have seen the birth and death of stars, supernovae, black holes and pulsars. They've seen planets torn to pieces and solar systems form. They've seen galaxies coalesce and skies darken.
The universe is much more grand, more amazing, more beautiful, more elegant and more subtle than has ever been written in any holy book, and you are here, against nigh-incalculable odds, to see it all. Just consider that for a moment.