I learnt the basics of the spreadsheet program in the nineties, just finishing the university. At that moment I found it the perfect tool! I could be used for almost everything.. and each new version came loaded with more and more features...I loved it! ... but then, i started to understand how it worked... and realized that it is just a tool, a good one,.. but just as good as the user that handles it...
Later on, in all my trainings to my fellow colleagues I always said pretty much the same: beware of the tool! it can hide mistakes and nobody will ever look for it! beware of the formulas, beware of the typing directly in a formula, beware of the references,....
Now, that even monetary policies (http://bit.ly/13kcmU2) are driven by EXCEL ... this warnings are more useful than ever..