Good post Alycidon.
I remember obtaining my ATPL on around 1700 hours and feeling a swelling of self-confidence, yet it was only at the end of my command course, when I had more than double the hours, that I realised how much I didn't know.
They say that ignorance is bliss. True. Donald was right. There are indeed known unknowns. I know that now. It's the unknown unknowns that catch you out. I didn't know that then.