Grin or Grimace

Grin or grimace, can you tell?
A knowing look, it's just as well.
Wrinkles born of a million smiles
Collected over years and a million miles.
Exposed to a lot, in a few short years
Weathered by much, watered by tears.
We've seen the range from heavenly highs
To deepest despair, heartbroken goodbyes.
We've traveled so far in life's Great Race
We've traveled so far, and never left this place.