The first requisite for success is to develop the ability to focus and apply your mental and physical energies to the problem at hand - without growing weary. Because such thinking is often difficult, there seems to be no limit to which some people will go to avoid the effort and labor that is associated with it.

Thomas Edison

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas Edison

If you’re not going to make a difference, get out of my way.

Bono

Iedereen die een nieuw idee heeft en de wereld wil veranderen, zal meer bereiken door storytelling dan door logische argumentatie.

Steve Denning

Live as if you were to die tomorrow. Learn as if you were to live forever.

Mahatma Ghandi

All truths are easy to understand once they are discovered; the point is to discover them.

Galileo Galilei

Live, love, learn and leave a legacy.

Stephen Covey

You can have it good, fast, or cheap: pick any two. 

If I asked my customers what they want, they simply would have said a faster horse.

Henry Ford

Few people request influence when their world is behaving rationally. As a result, consultants tend to see more than their fair share of irrationality.

Gerald M. Weinberg (The Secrets of Consulting)

Software and hard drugs are the only two professions that refer to their customers as 'users'. 

What's your biggest problem?
Events, dear boy, events.

Harold Macmillan 

The purpose of war is not battle but victory.

Sun Tsu (The Art of War, ca 500 BC)  

If the only tool you have is a hammer, you tend to see every problem as a nail.

Abraham Maslow

The first 90 percent of the code accounts for the first 90 percent of the development time. The remaining 10 percent of the code accounts for the other 90 percent of the development time.

Tom Cargill

A factor present in every successful project and absent in every unsuccessful project is sufficient attention to requirements.

Suzanne & James Robertson 

If you can not measure it, you can not improve it.

Lord Kelvin 

Perfection of means, and confusion of goals
seem, in my opinion, to characterize our age.

Albert Einstein
 

Testing can show the presence of bugs, but never their absence.

Edsger Dijkstra 

Management is doing things right; leadership is doing the right things.

Peter Drucker

Perfection is not when there's nothing to add, but when there's nothing to take away. 

Antoine de Saint-Exupéry

People don't want to buy a quarter-inch drill.
They want a quarter-inch hole!

Theodore Levitt

I keep six honest serving-men
(They taught me all I knew)
Their names are What and Why and When
And How and Where and Who.

Rudyard Kipling

If you don't know where you're going, you're unlikely to end up there.

Forrest Gump

There is nothing so useless as doing efficiently that which should not be done at all.

Peter Drucker