"I was walking across a courtyard to breakfast at a conference," recalled Herb Wilf, a combinatorialist at the University of Pennsylvania, "and Erdos, who had just had breakfast, was walking in the opposite direction. When our paths crossed, I offered my customary greeting, 'Good morning, Paul. How are you today?' He stopped dead in his tracks. Out of respect and deference, I stopped too. We just stood there silently. He was taking my question very seriously, giving it the same consideration he would if I had asked him about the asymptotics of partition theory. His whole life was spent thinking hard about serious mathematical questions, and he treated this one no differently. Finally, after much reflection, he said, 'Herbert, today I am very sad.' And I said, 'I am sorry to hear that. Why are you sad, Paul?' He said, 'I am sad because I miss my mother. She is dead, you know.' I said, 'I know that, Paul. I know her death was very sad for you and for many of us, too. But wasn't that about five years ago?' He said, 'Yes, it was. But I miss her very much.' We stood there silently for a few awkward moments and then went our separate ways."
-- Paul Hoffman, THE MAN WHO LOVED ONLY NUMBERS
(biography of mathematician Paul Erdos)
I have had some rough-ass days in my life, and if somebody asked me that on one of them and I were inclined to be honest about my feelings, I wish I could explain with the economy, grace, emotion, and composure Erdos exhibits in that exchange.
"Herbert, today I am very sad." Man, I *wish* I could just say it like that and be done. (Instead, it's either a long and tragic story or nothing at all.)