最优雅的证明是那些清晰地揭示问题本质的证明。

I have to be alone very often. I’d be quite happy if I spent from Saturday night until Monday morning alone in my apartment. That’s how I refuel.

Life is not worth living if it is not subject to reexamination.

Every book is a door that opens onto another world, and every reader is a traveler who steps through it.