In my car, I have a navigation system I dont know how we got along without one! It is not as smart as Mapquest, but it has an important added feature. While I am driving, it will recalculate my route and time after a false turn or a forced detour. It also updates the estimated time along the way based on the progress I have made already.
Now, think about planning for your future when you retire. No matter how good of a job you do, you still need to update the estimate over time. When you are just starting to plan for your future, a reasonable estimate about how much to save will help. But as you near retirement, you may want to know more detail before you decide to retire.
Delaying retirement can be a very powerful lever that you have in retirement preparation. The longer you work, the more you save and the less you take out for income.
The key is to start planning for your future NOW and dont stop! Being able to adapt to unforeseen changes in the world and in your life can make a tremendous positive impact on your future.