evidence: A more complete version of this quote is "Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude." [...] There is a story about a guy who had the right mental attitude. He worked for Apple, but the program he was working on was canceled. He still wanted to make it work, so he kept showing up, even though he was no longer on the payroll. Yes, he believed in his project so much that he was doing the work for free. [...] From: Twitter, @Smart_Quotes confirmed at : http://www.brainyquote.com/quotes/quotes/t/thomasjeff120994.html