Since I was putting up pics of my old shoes vs the new ones, I figured i'd show the tread too.... or lack there of in one case. Lol. But yah, I suppose years of wear and tear, harsh cleaning agents and various other chemicals, fire, animals, the excessive dryness, heat, and alkaline properties of the desert, and the running over miles of grass, dirt, rock, asphalt, and lots of other stuff will do that to a shoe. Either way, these are the best shoes I've ever owned and for $30 they've lasted the longest and were amazingly comfortable for the 5 years I had them.