Golf balls are almost purely polymeric, what with the Surlyn coatings, the rubber windings and the rubber enclosing the liquid. (I used to love cutting open golf balls when I was young - except for the solid one-piece balls which were boring. Compare that with the excitement of having stretch rubber flying everywhere as you rapidly attack the ball with a hacksaw.)
And yet very few golf balls are disposed of in the trash. Maybe the pros can keep a ball long enough that they decide to toss it, but for the rest of us, we shoot them until we lose them. And that ends up being a huge amount of balls, some 300 million in the US alone. And since very few are kept or disposed of in the trash, I have to believe that 299 million of those are lost every year.
Of course, the ultmate lost golf balls would be the two golf balls on the moon - although I would guess that after 29+ years of continuous exposure (even with half of it was during the long lunar nights) very little resiliancy is left in them. All the polymer chains must be scissioned into near nothingness.