I've kept a spreadsheet of my personal finances for the last 19 years. I have recorded all income and expenditure on a monthly basis, updated nett worth every month and projected forward how many years I can maintain my current standard of living, should I choose to retire in the following month. I'd like to think that I have covered all eventualities and won't be subject to any nasty surprises in the years ahead.
But what's the point of living if that's how you spend your time?
(Don't mean to be rude, but that kind of organisation is not for me)