The finish line is a human agreement imposed on a road that continues beyond it.

A finish line is a decision imposed on ground that keeps going. The road does not end; someone chose a point, and everyone agreed to treat crossing it as completion. The achievement is real and its boundary is invented.

This is a useful thing to remember about your own goals. The target you set is a chosen point rather than a natural endpoint, which means both that reaching it is genuinely worth marking and that the road continuing afterwards is not a failure of the goal. Many people feel flat after finishing something because they expected the road to end where their line was.