Which dictionary do you get your definition from? It is impossible not to be aware of certain truths through no fault of your own?
What is your definition of truly ignorant?
What is your definition of invincibly ignorant?
Some people believe that invincibly ignorant equates to being stubborn.
To me saying that invincible ignorance exists is to deny the omnipotence of God.
After all, it is scripture that it is God who chooses us and not we who choose God.