We may think there is willpower involved, but more likely... change is due to want power. Wanting the new addiction more than the old one. Wanting the new me in preference to the person I am now.
I was in uniform for four years, and I know that heroism doesn't occur from taking orders, but rather from people who through their own willpower and strength are willing to sacrifice their lives for an idea.
There's no doubt that Mexican men and women full of dignity, willpower and a capacity for work are doing the work that not even blacks want to do in the United States.