Stephen Hawking died early in the morning on March 14, 2018 — Pi Day and Albert Einstein’s birthday— but left behind one of the most incredible legacies for a human being on Earth.

Hawking was a theoretical physicist who pioneered new understandings of black holes and the cosmos at large. What’s more, he did so while struggling with a severe neurodegenerative disease that confined him to a wheelchair for the vast majority of his life.

The world-renowned scientist carefully contemplated and composed his thoughts with a special eye-tracking computer, and those words — many of them humorous— continue to inspire generations of people who were curious about how the universe works, where it came from, and where it may be headed.

Hawking supplied no shortage of remarkable insights about life, love, and science. Below, we’ve done our best to collect the most memorable things he said in his books, essays, interviews, TV show appearances, and more.