Here's a list of reasons why we save. A lot of things can go wrong.
- Age to die
- Need for extraordinary health care
- Close relative needs money
- Loss of uninsured items
- Replace items that wear out
- -Roof replacement
- -Water heater, furnace, washer/dryer
- -Painting inside and out
I especially like the "Etc." You can add to the list your own uncertainties. Taken altogether, the list of uncertainties is why it's so hard to know how much to save for today and for tomorrow.
The list comes from a recent paper by Bud Hebeler. You can look at on his website here. I'd recommend taking a look at it.