It is necessary, I believe, to accept this idea, not only for science, but also for other things; it is of great value to acknowledge ignorance.  It is a fact that when we make decisions in our life we don't necessarily know that we are making them correctly; we only think that we are doing the best we can – and that is what we should do.

To follow your path and not worry about what to do too much; one thing leads to the next, and you wind up where you’re meant to be.

Life’s too short to take offence.

Stay out of other people’s business.

I cannot pretend I am without fear. But my predominant feeling is one of gratitude. I have loved and been loved; I have been given much and I have given something in return; I have read and traveled and thought and written. I have had an intercourse with the world, the special intercourse of writers and readers. Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and adventure.

The first biography I read — I think the first scientific biography — was Madame Curie . And my mother, who was a surgeon, worked at the Marie Curie Hospital. She’d met Marie Curie, who was one of her great heroines. And reading the book, I think, was the first portrait of a scientist and the romance of a scientific life.

On the contrary, I feel intensely alive, and I want and hope in the time that remains to deepen my friendships, to say farewell to those I love, to write more, to travel if I have the strength, to achieve new levels of understanding and insight. This will involve audacity, clarity and plain speaking; trying to straighten my accounts with the world. But there will be time, too, for some fun (and even some silliness, as well).

I’ve had this concern all the time, but I can only hope that if one writes with appreciation and delicacy and respect, then it’s okay. I have to say that I’ve written a hundred times as much as I’ve published, because if there’s any thought of offense or embarrassment, then I will put the thing quietly away.

I feel a sudden clear focus and perspective. There is no time for anything inessential. I must focus on myself, my work and my friends. I shall no longer look at “NewsHour” every night. I shall no longer pay any attention to politics or arguments about global warming. This is not indifference but detachment — I still care deeply about the Middle East, about global warming, about growing inequality, but these are no longer my business; they belong to the future. I rejoice when I meet gifted young people — even the one who biopsied and diagnosed my metastases. I feel the future is in good hands.

The peace of the Sabbath, of a stopped world, a time outside time, was palpable, infused everything, and I found myself drenched with a wistfulness, something akin to nostalgia, wondering what if: What if A and B and C had been different? What sort of person might I have been? What sort of a life might I have lived?