Ahaa,in my country there is a sentence from a classic poem can explain this quote exactly: "年年岁岁花相似，岁岁年年人不同." It means we don't care the tiny changes untill it accumulates to a big one!
From generation to generation the players will change, but the story remains the same and is repeated.
We are all the same, humans beget more humans, cells beget more cells, that never changes. But the people who make it a world are changing from generation to generation, so it is always a different world. Even though it is the same. Does that make sense?
Indubitably ShannonMarie. The old trees may individually die and be replaced by saplings but the overall forest remains, apparently unchanging.