Those who cannot remember the past are condemned to repeat it.

I highly recommend this book if you find yourself on a tech project that involves software engineering, managing one or wondering why the hell your product has not been launched yet. This book was first published in 1975 so the technology references are rather outdated.

I first read this book in 2005 and was surprised that many of the mistakes made some 30 years prior were being made all over again on the projects I was involved with at my employer at the time. Actually quite disheartened to the point that it was clear we were on a death march if things didn't change drastically.

If you aren't into or don't have the time to read the book, you can find a decent summary at WikiPedia.

The full quote featured in the title is as follows:

"Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it."

--George Santayana, The Life of Reason (Great Books in Philosophy)