"The start is what stops most people" I believe that this means that it is always the hardest to start something new and that those first moments are what stop people from continuing.
Never look down on someone... unless you're helping them up. This means, to me at least, that you should never look at someone like they are worse unless you are helping them be better.
"You're Braver than you believe, Stronger than you seem, and Smarter than you think." Is a very good quote that really helps you understand that we humans are for the most part better than we like to think.
I believe that the quote by Richard D. Rosen means that you shouldn't just want to have something and that you should instead ask yourself what you are going to do to get there.