http://www.mydesert.com/article/20110123/BUSINESS/101220362/Tesla-CEO-Elon-Musk-talks-clean-tech
“You should not give up unless you're forced to give up — unless there's no other choice,” he said. “That principle can be misapplied if you're trying to penetrate a brick wall with your head.“If you're convinced what you're doing is correct, you should never give up.”