Don't Reinvent The Wheel, Unless You Plan on Learning More About Wheels

Reinventing the wheel is fun for the developer and good for him (he gets to learn how to make the wheel, etc.)

But for the customer, 99% of the time, the original wheel is good enough and all you are doing is wasting their money/time.

Please - from a client of many software projects, build me something that works in the quickest time possible! Don’t reinvent unless it is a critical success factor FOR THE CUSTOMER!