Comment by sg0

Thanks for sharing this. "Once, after I suggested a problem, he[Frigyes Riesz] he repeated it slowly twice to make certain he understood. Then, absolute silence. After half an hour, he exclaimed "Ja uj. I have it. Yes, I have it.", and he leaned to me, his eyes full of joy and mischief. But that was the end of it. He never made me privy to his solution." - We can learn a lot by working with individuals like these, who sometimes reveal nothing about their method in solving a problem, evoking (mild) stress/frustration upon others until they too solve the problem or at least spend some good time thinking about it.