So I've had a good memory, never took notes and sort of survived, often by looking at other people's notebooks, it's sort of unfair, but now I find my memory seems much worse I like to believe that it’s just that I’ve exceeded my storage capacity, which you don't know. But so much in success is, you know, associating one fact with another fact, something explains something. So having a lot stored in your brain and being able to bring it forth certainly, I think it has to be at the heart of a lot of creativity. You just, you try many more possibilities than other people. So maybe I have a high IQ for actually what is counted in making me successful, but I find, you know, when Seymour Benzer was, you know, 86 just before he died, I still found him a formidable intellect. He probably couldn't recall names as fast, but his brain was still very- And I was with Aaron Klug two days ago and he seemed so frail, coughing, but boy, when you got him talking about science, he was great. So he still, you know, was highly competitive at wanting to be first or, you know, his friends first. And so - you know, Sydney Brenner is still pretty formidable. And Francis didn't seem to fall off absolutely at all. He was, you know, had an article when he died of cancer at 86. So I'm hoping I can have fun out of science at least another five years. But it's very hard to find a role model who's in his 90s. One, there are few of them, but you know, the - Paul Zamecnik, who with Mahlon Hoagland did all the great work in the 50s on establishing in vitro systems for - he's still doing science at 95. He saw me at a Cambridge Massachusetts Legal Sea Foods and waved to me. And I went over, I didn't recognize him, and he's still at work. So you know, I have one role model if Paul can keep it up. And my tennis at 81 is certainly better than at any time in my life, so I'm almost able to play at a college level. And I think that's because I didn't play any really between the ages of 20 and 65 so I never wore my body out and I never tried to put a lot of top spin on it or something which, you know, Andy Murray's wrist is going.