Exactly 5,126 attempts to make the first bagless vacuum cleaner were failures-some catastrophic disappointments, some minor defects. It took 15 years. Prototype 5,127 was the success ... Failure is painful, but it spurs on improvement like nothing else.

As an engineer I'm constantly spotting problems and plotting how to solve them.

Failure is an enigma. You worry about it, and it teaches you something.

Success is made of 99% failure.

Life is a mountain of solvable problems and I enjoy that.

All our engineers are designers and all our designers are engineers.

Having a good idea is one thing, but persuading other people to buy it is quite another. Good inventors are polymaths: they think with their hands and their brains. They're experts in design, engineering and business.