Can the Istari really forget things?

Question

Gandalf the Istar was about 2,000 years old and had the appearance of an old man.

That is a lot of time to be walking the earth. A lot for a 'human' brain to take in. The Istari seem to have some human failings: Saruman has greed and lust for power, Gandalf seems rather fond of pipe weed. Do these mortal weaknesses extend to forgetfulness?

Forgetting things would seem to be a bit of a disadvantage to someone so old. There are a couple of times this seems to occur:

• In Moria, Gandalf gets to a junction and says "I have no memory of this place at all" This could just be as they are disorientated in the darkness.

• When discussing the other wizards Gandalf doesn't know the names of the blue wizards (this may be just in the films, and a reference to them being unnamed)

Do the Istari in their earthly forms forget things?

Answer 1

He can certainly forget things temporarily

There are a couple of examples of Gandalf forgetting things, though he seems able to recall them eventually:

• 'I once knew every spell in all the tongues of Elves or Men or Orcs that was ever used for such a purpose. I can still remember ten score of them without searching in my mind.

  ^{Fellowship of the Ring Book II Chapter 4: "A Journey in the Dark"}

• [Thráin] gave the map and the key to me. 'For my son,' he said; and then he died, and soon after I escaped myself. I stowed the things away, and by some warning of my heart I kept them always with me, safe, but soon almost forgotten. I had other business in Dol Guldur more important and perilous than all the treasure of Erebor.

  "Now I remembered it all again, and it seemed clear that I had heard the last words of Thráin the Second

  ^{Unfinished Tales Part 3: "The Third Age" Chapter III: "The Quest of Erebor"}

Whether or not he can forget things permanently is unclear, though I'd be inclined to argue "no"; if Elrond is any indication, the Elves don't seem to forget a whole lot:

'You remember?' said Frodo, speaking his thought aloud in his astonishment. 'But I thought,' he stammered as Elrond turned towards him, 'I thought that the fall of Gil-galad was a long age ago.'

'So it was indeed,' answered Elrond gravely. 'But my memory reaches back even to the Elder Days.

^{Fellowship of the Ring Book II Chapter 2: "The Council of Elrond"}

Whatever bodied limitations have been placed on the Istari, their immortal spirits (of which Elves are alike in kind, if not in degree) make them more similar to Elves than to Men.

Answer 2

Perhaps

There is little evidence in Tolkien's writing, but I'm going to take a slightly different tack than Jason does in his excellent answer. I suggest that the minds (not just the bodies) of the Istari were affected by their incarnation.

The longest writing on the Istari is the essay in Unfinished Tales. The origin of the Istari is described like this:

For with the consent of Eru they sent members of their own high order, but clad in bodies of as of Men, real and not feigned, but subject to the fears and pains and weariness of earth, able to hunger and thirst and be slain; though because of their noble spirits they did not die, and aged only by the cares and labours of many long years.

_{Unfinished Tales Part 4, II: The Istari}

I think that the fact that they were subject to the "fears" as well as the "pains and weariness of earth" suggests that their minds were not untouched.

A note attached to the essay tells us

For it is said indeed that being embodied the Istari had needs to learn much anew by slow experience, and though they knew whence they came the memory of the Blessed Realm was to them a vision from afar off, for which (so long as they remained true to their mission) they yearned exceedingly.

_{Unfinished Tales Part 4, II: The Istari}

Another note describes a council of the Valar where it is decided to send the Istari to Middle Earth.

"Who would go? For they must be mighty, peers of Sauron, but must forgo might, and clothe themselves in flesh so as to treat on equality and win the trust of Elves and Men. But this would imperil them, dimming their wisdom and knowledge, and confusing them with fears, cares, and weariness coming from the flesh."

_{Unfinished Tales Part 4, II: The Istari}

This passage not only mentions that the Istari are subject to the fears coming from the flesh, it states that their wisdom and knowledge are dimmed.

Conclusion

I think these passages suggest (but don't prove) that the minds, as well as the bodies, of Istari became "of the earth" (better not say human). Their memories are no doubt impressive, but may not be infallible.

Answer 3

One downside of extremely long-lived (or immortal) characters that doesn't come up much is the problem of memory. While such a character may never forget, it might take a while to call up a particular memory. I'm always reminded of this scene from Rudyard Kipling's The Jungle Books, where the very old giant snake, Kaa, tries to remember an event from his youth:

from Red Dog:

    [Mowgli] “Alala! If we die, we die. It will be most good hunting. But my stomach is young, and I have not seen many Rains. I am not wise nor strong. Hast thou a better plan, Kaa?”
    [Kaa] “I have seen a hundred and a hundred Rains. Ere Hathi cast his milk-tushes my trail was big in the dust. By the First Egg I am older than many trees, and I have seen all that the Jungle has done.”
    “But this is new hunting,” said Mowgli. “Never before have the dhole crossed our trail.”
    “What is has been. What will be is no more than a forgotten year striking backward. Be still while I count those my years.”
    For a long hour Mowgli lay back among the coils, while Kaa, his head motionless on the ground, thought of all that he had seen and known since the day he came from the egg. The light seemed to go out of his eyes and leave them like stale opals, and now and again he made little stiff passes with his head, right and left, as though he were hunting in his sleep. Mowgli dozed quietly, for he knew that there is nothing like sleep before hunting, and he was trained to take it at any hour of the day or night.
    Then he felt Kaa’s back grow bigger and broader below him as the huge python puffed himself out, hissing with the noise of a sword drawn from a steel scabbard.
    “I have seen all the dead seasons,” Kaa said at last, “and the great trees and the old elephants, and the rocks that were bare and sharp-pointed ere the moss grew. Art thou still alive, Manling?”
    “It is only a little after moonset,” said Mowgli. “I do not understand—”
    “Hssh! I am again Kaa. I knew it was but a little time. Now we will go to the river, and I will show thee what is to be done against the dhole.”