“I have looked in the mirror every morning and asked myself: "If today were the last day of my life, would I want to do what I am about to do today?" And whenever the answer has been "No" for too many days in a row, I know I need to change something.”
2005-09, Address at Stanford University (2005)
Context: When I was 17, I read a quote that went something like: "If you live each day as if it was your last, someday you'll most certainly be right." It made an impression on me, and since then, for the past 33 years, I have looked in the mirror every morning and asked myself: "If today were the last day of my life, would I want to do what I am about to do today?" And whenever the answer has been "No" for too many days in a row, I know I need to change something.
Help us to complete the source, original and additional information
Steve Jobs 150
American entrepreneur and co-founder of Apple Inc. 1955–2011Related quotes
Bishop Tylka shares hopes for ordination, explains motto in Catholic Post interview https://thecatholicpost.com/2020/07/16/bishop-tylka-shares-hopes-for-ordination-explains-motto-in-catholic-post-interview/ (16 July 2020)

“Every day, I define myself. I know who I am today. I don't promise you anything for tomorrow”
we can have an interview and that's completely different!
And you know what else? I am grateful to the bombshell because if it hadn't gotten me where it had gotten me, I wouldn't be where I am today. But this bombshell thing; it's old now. It served me. And I got out of it in time to keep from serving it. I used to think, I can't wait until 35, when people think I'm too old to be a bombshell. Maybe I'll get the good parts. But it wouldn't have happened that way. … Just because your boobs are saggy doesn't mean you get great roles. You're disposable.
O interview (2003)

Letter to Judge Lance Ito, requesting clemency for Charles Keating (January 18 1992), as quoted by Christopher Hitchens in The Missionary Position http://books.google.com/books?id=PTgJIjK67rEC&pg=PA11&dq=%22I+think+it+is+very+beautiful+for+the+poor+to+accept+their+lot%22, (Verso, 1995), page 67
1990s
“For a thousand years I have been asking myself, "what will I do now?" And still I need not answer.”
Desde hace mil años me pregunto: ¿qué haré ahora? Y aún no necesito responderme.
Voces (1943)

"I spend my days preparing for life, not for death" The Guardian, Laura Smith (2007-10-25)

quote of 1953; as cited in Smithsonian magazine.
Variants:
Every morning when I wake up, I experience an exquisite joy — the joy of being Salvador Dalí — and I ask myself in rapture: What wonderful things is this Salvador Dalí going to accomplish today?
Every morning when I awake, the greatest of joys is mine: that of being Salvador Dalí.
Quotes of Salvador Dali, 1951 - 1960