Everyone has abilities that come naturally to them, e.g.--public speaking. Those skill sets can be enhanced with further development. That is playing to a 'strength'. Eliminating or changing a weakness will that take much more deliberation, cognition, and skill enhancement to change. When it comes to crunch time, the natural inclination will be to use a strength.
A real teacher can help a person identify their natural strengths and fine tune them; help also to identify a weakness & ways to lessen, mitigate or transition into a strength.