On several occasions, Hawking advocated for living the best life you can.

“Remember to look up at the stars and not down at your feet,” Hawking said in the birthday message. “Try to make sense of what you see and about what makes the universe exist. Be curious.”

Hawking also refused to allow his disability to hold him back physically, mentally or spiritually.

“I don’t have much positive to say about motor neuron disease. But it taught me not to pity myself, because others were worse off and to get on with what I still could do,” Hawking told The New York Times. “I’m happier now than before I developed the condition. I am lucky to be working in theoretical physics, one of the few areas in which disability is not a serious handicap.”

He also advised that other people suffering from serious illnesses to not “be disabled in spirit.”