Guy Kawasaki wrote a really interesting post on his blog:
"Why Smart People Do Dumb Things" (Like Not Backup Their Hard Disk).
His post wasn't intended to be about making backups but merely about the flaws of the immature human mind. Guy's experience came from a failing hard disk. My latest encounter with the "god of stupidity" was after synchronizing my new PDA at home and at work. In the process I lost several contacts.
Why Guy did not make a backup of his hard disk? For him the question was answered in this book: "Why Smart People Do Dumb Things". In this book the authors list four reasons why smart people -like you and me- should know better ...