"The brick walls are not there to keep us out. The brick walls are there to give us a chance to show how badly we want something."
If you haven't heard this phrase, you really should watch his "Last Lecture": http://www.youtube.com/watch?v=ji5_MqicxSo
I think most motivational content is a scam because it is heavily tilted/skewed in favor of positive-only (e.g. don't talk about real failures). Randy Pausch wasn't trying to make a motivational speech - he was trying to deliver an important message (to his kids). He was real and passionate.
He never gave up and after a brief stint at Lucasfilm went onto founding Pixar with Ed Catmull and Steve Jobs.
Disney ended up purchasing Pixar in 2006 for about $7.4 billion