Clarifying the Weakness

My strength is made perfect in weakness...
My grace is sufficient for you....
In my weakness He is strong....

I've been struggling with, digging through, and exploring this verse for about two months ago. God obviously wants to get it into my head. It stuck out to me a few weeks before a conference, was the theme of a conference I went to, was the theme at youth and bible studies several times, and constantly pops into my head when my weaknesses are apparent. Something which comes up fairly regularly as of late it seems.
So, my Mom tells me about a book she read concerning personality types. I was very interested and began reading it today. From a quote I got from the book, I felt like I had had an epiphony. I think God is finally bringing all of this together....
"Because temperment is built into you at conception, temperment change is not possible. But changing your weaknesses is another story. As we will see, God, through the Holy Spirit, will provide strength for every human (or temperment) weakness. The result will be an increase in your strengths and how God can use you and a decrease in the impact of your weaknesses".