Last week, we lost one of the greatest thinkers of our time, Stephen Hawking. The world grieves the loss of this brilliant mind who brought so many new ideas to the scientific community, but those closest to him, his children, Lucy, Robert, and Tim, are suffering the painful passing of a doting father.

In a 2010 ABC News interview conducted by Diane Sawyer, the late physicist revealed three very important pieces of advice that, Hawking said, he always made sure to pass along to his children. Interestingly, none of the three suggestions have anything to do with science, the universe, or how to decode the inner-workings of a black hole.

Instead, his guidance focused more on the essentials of life: mindset, purpose, and even love. Here’s a bit of Hawking’s fatherly advice:

1. Optimism is the only way

   “Remember to look up at the stars and not down at your feet.”

2. Find work that you’re passionate about and devote yourself to it

   “Never give up work. Work gives you meaning and purpose and life is empty without it.”

3. True love should never be ignored

   “If you are lucky enough to find love, remember that it’s rare and don’t throw it away.”

Now, if you are surprised by Hawking’s warm and sweet fatherly advice, you surely haven’t been exposed to the scientist’s sense of humor. He had an arsenal of uplifting—and usually funny! —quotes that he loved to share during his long career. Here’s what he had to say on the subject of black holes, for instance:

“Black holes ain’t as black as they are painted. They are not the eternal prisons they were once thought. Things can get out of a black hole, both to the outside, and possibly, to another universe. So, if you feel you are in a black hole, don’t give up. There’s a way out.”

Yep, the man sure had quite the hopeful perspective on the universe and our role in it. Yet another reason why Hawking will be missed so dearly!

A physicist and a father remembered

Out of his three children, Lucy, Hawking’s only daughter, has been the most instrumental in keeping his legacy alive. She works as an author and has penned several children’s books that focus on science. In fact, she has even been awarded a ‘fellow’ title from the Royal Astronomical Society for her contributions to the scientific community.

Lucy was also said to be the closest to her father, a fact that makes the statement that she released following his death just that much more heart-wrenching…

We are deeply saddened that our beloved father passed away today. He was a great scientist and an extraordinary man whose work and legacy will live on for many years. His courage and persistence with his brilliance and humor inspired people across the world. He once said, ‘It would not be much of a universe if it wasn’t home to the people you love.’ We will miss him forever.

Anyone who has ever lost a parent understands Lucy’s words all too well. R.I.P. Stephen Hawking—we’ll be sure to hold your sweet words close to our hearts.

We’d love to hear your thoughts on Stephen Hawking’s fatherly advice. Did you receive similar guidance when you were a child? What life skills would you like to pass down to your children? What is your all-time favorite Stephen Hawking quote?