Leo Tolstoy — We regret losing a purse full of money…

We regret losing a purse full of money, but a good thought which has come to us, which we’ve heard or read, a thought which we should have remembered and applied to our life, which could have improved the world- we lose this thought and promptly forget about it, and we do not regret it, though it is more precious than millions.
Leo Tolstoy