I modestly declared myself to be quite unequal to the task imposed upon me--and I privately felt, all the time, that I was quite clever enough to perform it, if I only gave my own abilities a fair chance.

Mr.Franklin, I imagine, must have seen my private sentiments in my face.

He declined to believe in my modesty; and he insisted on giving my abilities a fair chance.
Two hours have passed since Mr.Franklin left me.

As soon as his back was turned, I went to my writing desk to start the story.

There I have sat helpless (in spite of my abilities) ever since; seeing what Robinson Crusoe saw, as quoted above--namely, the folly of beginning a work before we count the cost, and before we judge rightly of our own strength to go through with it.