:optimism: n. What a programmer is full of after fixing
the last bug and just before actually discovering the *next*
last bug. Fred Brooks's book "The Mythical Man-Month" (See
"Brooks's Law") contains the following paragraph that describes
this extremely well:
All programmers are optimists. Perhaps this
modern sorcery especially attracts those who believe in happy
endings and fairy god-mothers. Perhaps the hundreds of nitty
frustrations drive away all but those who habitually focus on the
end goal. Perhaps it is merely that computers are young,
programmers are younger, and the young are always optimists. But
however the selection process works, the result is indisputable:
"This time it will surely run," or "I just found the last bug.".
See also {Lubarsky's Law of Cybernetic Entomology}.
-- The AI Hackers Dictionary