Second System Effect
An architect's first work is apt to be spare and clean. He knows he doesn't
know what he's doing, so he does it carefully and with great restraint.
As he designs the first work, frill after frill and embellishment after
embellishment occur to him. These get stored away to be used "next time". Sooner
or later the first system is finished, and the architect, with firm confidence
and a demonstrated mastery of that class of systems, is ready to build a second
This second is the most dangerous system a man ever designs.
The Mythical Man Month, p. 55