Only dull people are brilliant at breakfast.
— Oscar Wilde, An Ideal Husband, 1893
I once had a post card with this phrase on it. I pinned it up in my office, because I am not brilliant at breakfast, or at least not until I have had coffee. The card had been there for barely a day, when I coincidentally learned from my boss, that he felt he “Did his best work first thing in the morning.” The postcard lived in my drawer for many years!