Beside every great success are the seeds of enormous failure. In every failure there's the opportunity seeds of great success. They're not miles apart. So if they're that close together and if you're really working you're always gonna have that likelihood that something's not going to work.
There is no need to worry about mere size. We do not necessarily respect a fat man more than a thin man. Sir Isaac Newton was very much smaller than a hippopotamus but we do not on that account value him less.