It is really useful to be reminded of your errors. I think Warren Buffett and I are pretty good at that. We do kind of mentally rub our own noses in our own mistakes. And that is a very good mental habit.
Don't be afraid to give your best to what seemingly are small jobs. Every time you conquer one it makes you that much stronger. If you do the little jobs well, the big ones will tend to take care of themselves.
Here is the prime condition of success: Concentrate your energy, thought and capital exclusively upon the business in which you are engaged. Having begun on one line, resolve to fight it out on that line, to lead in it, adopt every improvement, have the best machinery, and know the most about it.