“My mentality is that of a samurai. I would rather commit seppuku than fail.”

“I have made the mistaken assumption - and I will attempt to be better at this - of thinking that because somebody is on Twitter and is attacking me that it is open season. And that is my mistake.”

“I started SpaceX with the expectation of failure.”

“Even if producing CO2 was good for the environment, given that we're going to run out of hydrocarbons, we need to find some sustainable means of operating.”

“Optimism, pessimism, f**k that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work.”

“Fear, when your friends say to you what you have done well, and say it through; but when they stand with uncertain timid looks of respect and half-dislike, and must suspend their judgement for years to come, you may begin to hope.”

“Good criticism is very rare and always precious.”

“Criticism may not be agreeable, but it is necessary. It fulfils the same function as pain in the human body. It calls attention to an unhealthy state of things.”

“To wilful men, the injuries that they themselves procure must be their schoolmasters.”

“I hourly learn a doctrine of obedience.”

“Experience is by industry achieved, And perfected by the swift course of time.”

“Assume a virtue if you have it not.”

“Best men oft are moulded out of faults.”

“Mend when thou canst; be better at thy leisure.”