I've often wondered how in the world something that I perceive as a weakness could ever be anything good. But as I've thought about this and personally dealt with a situation that this would apply to, I've come to realize that the most common things that usually hold us back from having weaknesses turned to strengths are our own denial of the weakness, our inability to see it as something that can be changed, or our refusal to work with Christ to change it.
As an example, if someone is very sensitive, it can be either a strength or a weakness, depending on how they use it. To be sensitive to other people's feelings, needs, and comforts would be a tremendous blessing to others and a strength to oneself. But, if your sensitivity means that you are more apt to take offense, let minor things hurt your feelings, or that you lash out at others, the weakness not only continues to be a weakness to you, but can also weaken those around you.
It's all in how we use what we've been given. We can either turn to the Lord and seek to improve ourselves and let His atonement work to turn our weaknesses into strengths, or we can throw up our hands in defeat, use the excuse that it's just how we are, and reject the growth that the Savior wants us to experience. It's important to realize that the imperative to turn our weaknesses into strengths is not only for our own growth for also for the benefit of being a blessing in the lives of others. We're given weaknesses to keep us humble, but also to give us the opportunity of working with Christ to experience His enabling power. He truly can take our weakness and turn them into something good.