Pulitzer Prize-winning historian David McCullough is author of popular biographies such as Truman and John Adams, and at 79 years old, he’s still going strong. When asked by Harvard Business Review whether he is ready to retire, McCullough offered some interesting perspective on how he views his work through the American founders’ understanding of the “pursuit of happiness” (HT):

I can’t wait to get out of bed every morning. To me, it’s the only way to live. When the founders wrote about life, liberty, and the pursuit of happiness, they didn’t mean longer vacations and more comfortable hammocks. They meant the pursuit of learning. The love of learning. The pursuit of improvement and excellence. I keep telling students, Find work you love. Don’t concern yourself overly about how much money is involved or whether you’re ever going to be famous. I’m giving a talk at Dartmouth this week. It’s called the Hard Work of Writing. And it is hard work. But in hard work is happiness.