But, once there, it remained there; and hardened into a purpose than which I have never entertained a more determined purpose in my life.

I am far from sure that I believed there was anything hopeful in it, but my mind was thoroughly made up that it must be carried into execution.
Again, and again, and a hundred times again, since the night when the thought had first occurred to me and banished sleep, I had gone over that old story of my poor mother's about my birth, which it had been one of my great delights in the old time to hear her tell, and which I knew by heart.

My aunt walked into that story, and walked out of it, a dread and awful personage; but there was one little trait in her behaviour which I liked to dwell on, and which gave me some faint shadow of encouragement.

I could not forget how my mother had thought that she felt her touch her pretty hair with no ungentle hand; and though it might have been altogether my mother's fancy, and might have had no foundation whatever in fact, I made a little picture, out of it, of my terrible aunt relenting towards the girlish beauty that I recollected so well and loved so much, which softened the whole narrative.

It is very possible that it had been in my mind a long time, and had gradually engendered my determination.
As I did not even know where Miss Betsey lived, I wrote a long letter to Peggotty, and asked her, incidentally, if she remembered; pretending that I had heard of such a lady living at a certain place I named at random, and had a curiosity to know if it were the same.