@georgeob1,
And, if you DON'T live for 40 years after you retire, whatever you don't collect in benefits remains in the US treasury as general funds for Congress to spend on whatever. You aren't allowed to bequeath it to your wife or kids or grandkids as you can a private savings account. If you get hit by a bus the day you retire, the government gets it all.
There is also nothing in the Constitution or general law that would prevent Congress from changing, suspending, or stopping your benefits at any time they chose and there is absolutely nothing you could do about it. It would be political suicide of course, at least now, but they could do it.