Transferring mastery

Why is it that a person who has mastered one specific area of expertise sometimes is unable to become proficient at something else? No matter how much he/she tries (it seems), the approach to the basics is sloppy at best.

If this situation is familiar to you, here's what would help: remember that you are already an expert in one area so it's not like you don't know how to focus, study, set goals, and accomplish them. More specifically, think about why you are an expert in this area? What did it take you to go this far?

If you find an answer to these questions, if you figure out the strategy behind your expertise, transferring mastery from one area to another becomes just a matter of tactics and their execution.