James Dyson is the founder of Dyson, the maker of innovative vacuum cleaners, fans and more. He’s also the founder of the James Dyson Foundation, which supports science, design and engineering.

What was (or is) your best day at work?

The challenge with engineering is that you never know when you’ll have a breakthrough. Sometimes it’s the end result after building hundreds of prototypes and other times it’s a quick idea we’ve stumbled upon. These moments are incredibly exciting, but short-lived as there is always more testing and development to be done. But that’s part of the fun.

The worst?

Early on in my career I made the mistake of not patenting the Ballbarrow — which was a wheelbarrow with giant pneumatic ball rather than a wheel — in my own name. The company I worked for booted me out and I lost all rights to my invention. Ever since, I’ve fought tooth and nail to protect what’s mine.

Who is your hero in the work world?

My mentor Jeremy Fry took me on as an undergraduate when I was a student at the Royal College of Art and entrusted me with developing a high-speed landing craft called the Seatruck. Starting with a plank of wood as a hull, I was challenged to get my hands dirty and turn the concept into an actual working boat. Jeremy taught me that it’s better to take an iterative approach to a problem, where you adapt and improve on an idea one small step at a time rather than giving up at the first hurdle. Learning by doing is invaluable and he helped instill in me the idea that failure is a good thing.