I think it's probably not true that it all adds up over a lifetime. That's the model that is widely used but there's some good evidence to suggest it's not accu

I think it's probably not true that it all adds up over a lifetime. That's the model that is widely used but there's some good evidence to suggest it's not accurate. see: https://en.wikipedia.org/wiki/Linear_no-threshold_model https://en.wikipedia.org/wiki/Linear_no-threshold_model