For many years I worked for organizations that focused on driving excellence by regularly increasing performance expectations.
In essence, great achievement or success from the past became only mediocre in the present and perhaps even below expectation in the future.
Resting on your laurels
Having one successful book or a hit record or implementing the most complex project does not make for success. True greatness requires continually performing at a higher level.
Like the concept of infinity, raising the performance bar is never-ending. This applies even as you move through various stages of life.
For example, a student to professional to the leader and then retired, the quest for improvement and excellence does not need to end, in fact, should not end.
You Can Do It
When I was younger, I was engaged in competitive track and field. Two of my favorite events were high jumping and pole vaulting. In both cases, you attempted to jump over a bar without dislodging it.
Each successful attempt led to another after the bar had been raised of course. Ultimately the bar reached a height I could not jump over at that point.
This led to more training and preparation. At the next meet, I always beat my height by at least one raise of the bar. Until I stopped competing (admittedly there probably was a maximum height I could jump).
Challenging myself, proving I could do it was both motivation and a thrill (the thrill of success). From an early age, this taught me the value of pushing the bar.