If you are an entrepreneur (its a mind-state not a job function/title), there are 2 categories of thought that are subtly destructive:
Its easier to understand how the second item above is destructive. When when we think we are already there, complacency sets in. Complacency seeps through organizations like a virus and its just as hard to get rid of. When a challenge (competitor, changing product, etc.) for your business arises, complacency insures your inability to react.
The more subtly destructive though is “I have a destination.'” But wait, isn’t this what we were all taught? To have a goal and chase it? The destructive part is not the chase, its the focus on a particular destination. Self-focused destinations take the deep happiness out of the chase and makes it less likely that we can see it to the end.
Be happy. Enjoy the chase.