Not really. I have no kids, so I have to protect to fund my own medical care. I'm also protecting for the case that Social Security is not fully funded by the time I retire. Also, I currently live in Southern California, though I may retire elsewhere. My family history suggests a long retirement, as my grandparents all lived to their 90s, with one hitting 100, and as a kid I knew a couple of my great-grandparents who also lived into their late 90s.
I'm assuming expenses around $60,000 per year (this was computed in 2010 dollars). At 3% annual inflation, when I retire in 2045, that $60k is $168,832 per year. If I live to 100, that is $434,756/yr in 2077 dollars.
The sum total of expenses from 2045 to 2077 is $9,298,888. So the hope is that by hitting $5mil by 2045 that it will continue to grow to cover the rest. If it grows at 4%, I go broke at 101.