Such was the deadly sin of accidie, the name of which is forgotten today, though the thing itself is with us still.
For Envye blindeth the herte of a man, and Ire troubleth a man; and accidie maketh him hevy, thoghtful and wrawe.
During the great war the disease of accidie was prevalent in prison camps, as any account of Ruhleben shows very clearly.
Envye and Ire maken bitternesse in herte; which bitternesse is moder of accidie and binimeth him the love of alle goodnesse.
You hardly know why, but everything seems to go wrong; you seem oppressed with what old writers called "accidie."
Greek ἀκηδία; whence acedia or accidia in Latin; English accidie.
So when you think of these three men, it cannot be middle age or old age that really produce this accidie.