We are all exiles in some way, searching for a place to call home.

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.

它美丽而简单，就像所有真正伟大的骗局一样。

In chemistry, as in life, the most transformative reactions often require patience and precise conditions.