Assuming you are moving forward into new territory. Pushing beyond your boundaries. Working in ways to improve what you do, what your team does and what your company does, when your work has those challenges you need to divide the work in half. The first half is doing the work. The second half is learning from what you have done so that you can do it better the next time. You need to spend as much time learning from what you did, as you spent doing what you did.
And, if you don't know how to learn from the work you are about to do, then you should question whether the work should be done or not in the first place.