A recent experience at work has left me convinced that sometimes a bug is quite simply just meant to be. I do not refer mind you to bugs that choose to make an appearance only after the user has performed a jiggle in front of the monitor having muttered strange incantations while standing on his/her head with the planets aligned in just the right manner. I refer rather, to bugs that a blind man in a dark room would have been hard pressed to miss (now, if you feel the need to clarify with me the fine point of how a dark room can make the process of locating an object harder than it would otherwise have been to a blind man, then I strongly urge you to resist that need).
Any given feature in the product that I am working on must necessarily pass through the following quality checks before it ever sees the light of day. It must first negotiate a series of unit test cases cunningly designed to trip it up when it's not looking. It must then survive the traumatic experience of system testing where the entire development team has a go at it. This is followed by days upon days of unending torment by the quality assurance team. Only those features that display the resilience to pass through all this without blemish make it to the final release. And yet, a bug that failed the most basic of test cases managed to escape notice and show up in front of the customer!
Like I said, some bugs are just meant to be!