There are some things that time cannot mend… some hurts that go too deep… that have taken hold.
"Those who used the Nine Rings became mighty in their day, kings, sorcerers, and warriors of old. They obtained glory and great wealth, yet it turned to their undoing. They had, as it seemed, unending life, yet life became unendurable to them. They could walk, if they would, unseen by all eyes in this world beneath the sun, and they could see things in worlds invisible to mortal men; but too often they beheld only the phantoms and delusions of Sauron." - Of the Rings of Power and the Third Age, The Silmarillion
Nirnaeth Arnoediad ~ The Battle of Unnumbered Tears [F.A. 472]
’(…) Some have said that even then the Eldar might have won the day, had all their hosts proved faithful. For the Orcs wavered, and their onslaught was stayed, and already some were turning to flight. But even as the vanguard of Maedhros came upon the Orcs, Morgoth loosed his last strength, and Angband was emptied. There came wolves, and wolfriders, and there came Balrogs, and dragons, and Glaurung father of dragons. The strength and terror of the Great Worm were now great indeed, and Elves and Men withered before him.’