Whether they have forgotten — The Man in the Iron Mask

Whether they have forgotten 1
Or are forgetting now
Or never remembered-
Safer not to know-

Miseries of conjecture 5
Are a softer woe
Than a Fact of Iron
Hardened with I know-
(F.1334/J.1329)
[1–4] forgotten, Safer:: the narrator is the prisoner with iron mask under the reign of Louis the Fourteenth.
[7] Fact of Iron:: an iron mask on his face.
[8] with I know:: the prisoner knew something that caused his confinement.

The Man in the Iron Mask. It was in the reign of Louis the Fourteenth, according to a French historian, that an unknown prisoner, young, and of noble appearance, of distinguished height, and great beauty of person, was sent in profound secrecy to an island on the coast of Provence. The captive wore, while travelling, a mask so contrived by steel springs, that he could take his meals without uncovering his face, a strict order having been given that if he disclosed his features he should instantly be put to death. ─ The Saturday Magazine (1834)