Today, my parish at home got a new priest, and he gave a homily about humility, since today's second reading was, as you had said, 2 Corinthians 12:

.... When I am weak, then I am strong.

He talked about how boasting is not humility

Look how awesome I am in my skin-tight suit!

but denying talents isn't humility either.

Oh, you're too kind! That train practically stopped itself.

This ^ is called false humility, and is really just pride in disguise.

Humility, he said, is knowing exactly who you are and acting accordingly. 

If someone says, "The force is strong within you," then you don't say:

No, it's not, you're ridiculous!

But you also don't say:

I know, I shall use it to rule the universe!

You say:

I am honored to have been chosen, Please teach me.

That is humility. You know what else that sounds like, other than Star Wars?

My soul magnifies the Lord, and my spirit rejoices in God my Savior, for He has looked with favor on the lowliness of His servant. Surely, from now on all generations will call me blessed; for the Mighty One has done great things for me, and holy is His name. His mercy is for those who fear Him from generation to generation. He has shown strength with His arm; He has scattered the proud in the thoughts of their hearts. He has brought down the powerful from their thrones, and lifted up the lowly; He has filled the hungry with good things, and sent the rich away empty. He has helped His servant Israel, in remembrance of His mercy, according to the promise He made to our ancestors, to Abraham and to his descendants forever.  

Aside from her Son, Mary was the most humble person in the history (and future) of humanity. An angel shows up at her house praising her, which of course scares her, then that same angel tells her she's going to be the mother of God! I can think of a few responses I might have had to that request when I was a young teenager:

1. You're crazy! You were using the praise as a trick to get me to have a child. 
2. Why me? Why this? Why now? What kind of weird plan is this?
3. Give me proof! I don't believe you.
4. I'm not worthy. Pick someone else.
5. Mommy! There's a scary man calling me full of grace and trying to get me to have a baby!!! 

Mary's response, instead of any of those, was simply, "How?" and then "Yes."

She doesn't try to deny the graces God has granted her. Out of all the people in the Bible appointed by God for great tasks, Mary is the only one I can think of who doesn't claim to be unfit or unworthy. She trusts God to have picked someone who was capable of completing the task.

Rather than being silent afterwards, sulking in her room over having to do such a dangerous and difficult task or desperately trying to hide her pregnancy, Mary proclaims her Magnificat,  glorifying the Lord.

She thanks the Lord for giving her such an important role in salvation, even though her role is difficult. She does not shy away from her talents and the wonderful graces God has given her. Rather, she points out her graces (from this day, all generations will call me blessed) in order to glorify God.

True humility doesn't mean being a push-over. It means imitating Christ, who grew up imitating His  Blessed Mother.

God has blessed me in so many ways. I will not deny my Immaculate Conception, my response to the Annunciation, the Incarnation in my womb, my Assumption, my eternal reign in Heaven, or any of my other graces. All of this, though, I have received directly from God, who loves me and who blesses me so that I may lead you to Him, who loves you more than you could ever possibly imagine.

This is probably the longest blog post I have ever written for you. I should probably mention that the examples are all my own. The priest talked about singing as a talent and Jesus as an example of humility. Actually, his example was really good, because he talked about how humble Jesus was in today's Gospel reading. 

Anyway, I shall leave you now to ponder humility. 

I'm praying for you!

:)