I've always been very one-sided about science, and when I was younger, I concentrated almost all my effort on it.Richard Feynman
And it comes from saying no to 1,000 things to make sure we don't get on the wrong track or try to do too much. We're always thinking about new markets we could enter, but it's only by saying no that you can concentrate on the things that are really important.Steve Jobs
The first requisite for success is the ability to apply your physical and mental energies to one problem incessantly without growing weary.Thomas Edison
The reason we wouldn't make a seven-inch tablet isn't because we don't want to hit a price point, it's because we don't think you can make a great tablet with a seven-inch screen.Steve Jobs
As every divided kingdom falls, so every mind divided between many studies confounds and saps itself.Leonardo da Vinci
He, who every morning plans the transactions of the day, and follows that plan, carries a thread that will guide him through a labyrinth of the most busy life.Victor Hugo