I think we keep people long after they've left.
Sometimes unknowingly and sometimes purposefully, they become a part of us. You'll feel bits of them melded into you, in the songs you play when you're blasting down the highway, or in the adventures that pull at your heart strings.
You'll see them in sunrises, or on mountains you shared. In the way you smile, even in the sunglasses you wear. They're in the places you choose to visit, and revisit, time and time again. In the way you smile kinda like them, the way you wave your hands around enthusiastically while telling stories. You'll hear them in the ridiculous slang you picked up, the nicknames you've grown accustomed to, the words they always used that you've come to adopt as well.
And suddenly we realize, what we once figured as being solely of ourselves, is more a complex coming together of all the roots we've ever known, all woven one into the other.
We are the collective sum of everything and everyone we've experienced, loved, discovered, lost.