How can you expect to improve in your area of expertise, your chosen field, or as a person in general by focusing solely on your strengths? Everyone has a weakness; what differentiates those who succeed from those who do not is how those weaknesses are dealt with.
In "The Art of Learning", Josh Waitzkin discusses the necessity to identify your weaknesses and work on improving them until they no longer hold you back. In case you are not aware, Josh is the subject of the book and movie "Searching for Bobby Fischer".
He spent his youth mastering the game of chess and eventually moved on to another endeavor, Tai Chi Chuan Push Hands - a form of Chinese martial arts. Josh holds multiple National Championship titles and a World Championship title in push hands - and I would highly recommend reading his book. It describes in depth what it really takes to become world class.
In one passage, Josh describes an injury to his right shoulder, which he sustained in a push hands match. The shoulder needed months to heal, but it couldn't keep Josh off of the mat. Instead, he worked incessantly on utilizing his weaker left hand to control an opponent's right arm, and his left elbow to isolate attacks from the opponent at the same time. He trained in this manner constantly until his shoulder healed and became so proficient with his left hand that he felt he held an unfair advantage over his opponents once his right arm healed.
What would most people do in that situation? Sit on the sidelines and wait until their shoulder has healed? Give up training for the season and blame the injury? I don't want to be mistaken here; I'm not suggesting that if your leg is broken you should risk further complicating the injury by putting weight on it. What I am suggesting is that you use your creativity and assess what CAN be done in place of your standard training so that you continue to improve. You may open your mind to a new perspective that you never would have seen if you kept on your standard training regimen.
A physical weakness can be much easier to identify than a mental or psychological one. In his "Principles", Ray Dalio suggests writing out your weaknesses and keep the list in a handy location that can be reviewed or edited promptly when necessary. I keep my list as a draft in my e-mail. That way, I can always access it to keep myself in check when I start feeling over confident or identify another weakness that should be added. By regularly glancing at your list, you will always be cognizant of areas that might trip you up and can hopefully identify and avoid them before the become a more serious problem.
Here's the key: Listing out your weaknesses can be a difficult task, but the ultimate goal is to identify the ROOT cause of the weakness. Dalio gives an example: You are not late for the train because you didn't check the schedule (proximate cause). You are late for the train because you are irresponsible (root cause).
Once the root cause is identified, actions can be taken to correct it. If you are great at looking at the macro plan, the big picture - but you tend to miss the details, you have a couple of options. You can either surround yourself with others who are detail-oriented people or you can train yourself to focus on the details so they no longer act as a weakness. Make sense?
None of like to look in the mirror and focus on things we are not good at, but it is a small price to pay for the long term reward of doing so.