A brain is a society of very small, simple modules that cannot be said to be thinking, that are not smart in themselves. But when you have a network of them together, out of that arises a kind of smartness.
Trust your gut instinct over spreadsheets. There are too many variables in the real world that you simply can't put into a spreadsheet. Spreadsheets spit out results from your inexact assumptions and give you a false sense of security. In most cases, your heart and gut are still your best guide.
Of course, I do have a slight advantage over the rest of you. It helps in a pinch to be able to remind your bride that you gave up a throne for her.

