In his experience youth and age were the dangerous periods--youth, because it knew nothing of life, and age because it knew too much.

There were fewer surprises in middle-age.

That was the period of responsibility--when humanity clung to the ordered way with the painful rectitude of a procession of laden ants toiling up a hill.

Youth was not like that--nor age.
No, it was not that.

His difficulty was to fit all the circumstances into any compact theory of the case.