Paranoid Programming

Hey guys, I just saw The Bourne Trilogy and I want to know how to become a paranoid programmer.

The easiest way to become a paranoid programmer is to assume anything can fail (yes, even that innocuous d = d * -1;) and bring the whole application crashing down.  Once you're in that mindset, begin writing conditions to survive a failure of all offending lines of code.  And then write conditions to survive the failure conditions failing.  If you need to go any further, you may as well give up programming and take up poetry.