Study. Be honest. Don’t violate the laws and get in trouble. Get you a good spouse that will support you, because you never stop working and studying. The fact that you get the place just means you’ve started as far as the work and the pressure is concerned. That’s the only advice I’d know to give.

Life doesn't offer you the perfect opportunity at the perfect time. Opportunities come when you least expect them ... Rarely are opportunities presented to you in a perfect way. In a nice little box with a yellow bow on top. ‘Here, open it, it's perfect. You'll love it.’ Opportunities -- the good ones -- are messy, confusing and hard to recognize. They're risky. They challenge you.

So given a Time Turner, I would tell my 21-year-old self that personal happiness lies in knowing that life is not a check-list of acquisition or achievement. Your qualifications, your CV, are not your life, though you will meet many people of my age and older who confuse the two. Life is difficult, and complicated, and beyond anyone’s total control, and the humility to know that will enable you to survive its vicissitudes.

Everything I did, and I think everything Martin Luther King did, was because we allowed our lives to be in tune with what we felt to be a divine purpose. And it didn’t matter whether we lived or died. It didn’t matter how much money we made, or what we accomplished.

Clarity when I am writing.

I would love to have a better sense of physical balance.

The artist Gerhard Richter.

Tramping through the woods in South Jersey in 1957 with my dog Bambi.

Collapse of the imagination.