“As you will never be sure which are the right problems to work on, most of the time that you spend in the laboratory or at your desk will be wasted. If you want to be creative, then you will have to get used to spending most of your time not being creative, to being becalmed on the ocean of scientific knowledge.”

The Last Lecture (2008)

Source: First, Break All the Rules: What the World's Greatest Managers Do Differently

Future Proofing You (2021)

Source: Trading Up

Declaration at his 85th birthday party (6 January 1963), as quoted in The Best of Ralph McGill : Selected Columns (1980) by Ralph McGill, edited by Michael Strickland, Harry Davis, and Jeff Strickland, p. 82
Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
As quoted without source in The School Musician Director and Teacher Vol. 43 (1971) by the American School Band Directors' Association

Time Management (2007)
Context: Everyone has Good and Bad Times. Find your creative/thinking time. Defend it ruthlessly, spend it alone, maybe at home. Find your dead time. Schedule meetings, phone calls, and mundane stuff during it.