There is nothing happens to any person but what was in his power to go through with.

Taken strictly, that is a bigger claim than most lives support, and there are losses no one should be told they were built to carry. Taken loosely, it points at something people notice afterwards: the thing you were certain would break you turned out to be survivable in ways you could not have predicted beforehand. Capacity tends to show up during, not before.

When you are measuring a hard stretch in advance, remember the estimate is being made by someone who has not yet been through it. Ask what carried you through the last one. Start there rather than with the whole of it.