On the other hand, there are those who believe you need to first do and only then can you be. For example, a person who writes is a writer. You can't be a writer if you don't write.
I believe you need to be both at the same time. You need to visualize that you are before you can decide to take action, but you don't understand what it is to truly be yet. In other words, one can only visualize what a good baseball might be but only until he or she becomes a good baseball player does he or she knows what a good baseball player really is.
What all this means is one can find real learning and fulfillment in the hard work itself and not necessarily in the final expected outcome because that outcome might prove to be a disappointment.