Would you care to know the real reason the elves of Middle-Earth left for the Undying Lands? I could tell you, but the truth is not pretty; it's scattered with misunderstandings and superstition, but if you really insist . . .
Once upon a time, there was a happy, short, fun-loving folk called "hobbits." Now, hobbits are known for their appetites1, kindly disposition towards most folk2, and their inclination towards mischief3. In the book, The Fellowship of the Ring, by J.R.R. Tokien, four hobbits are off on a journey, which lands them in Imladris for a short while. Now, while two of those four hobbits are quite nice4, the other two (Merry and Pippin) lived up to the mischievous part of being a hobbit quite well, actually. As soon as the hobbits arrived at Imladris, the two pranksters were off like greyhounds, racehorses, etc.
Merry and Pippin were quite hungry after their long journey, so it only made sense that they should have eaten right away. However, the elves needed time to prepare, and the elves thought they explained it to the hobbits quite nicely. Obviously, the elves had never been in contact with a hobbit before . . .
Thus far, it had not been a good day for Lord Boromir, Captain of the White Tower.
Boromir, like any other traveler, wished to rest in peaceful accommodations after a long, tiring, and dangerous journey. However, instead of being immediately shown to his room as he should've been, he was kept waiting.
Lord Boromir hated waiting.
Why was he kept waiting? Well, apparently, strange little folk called "hobbits" were running amok. They were wreaking all sorts of havoc upon the poor, gallant elves of Imladris. There were two hobbits in particular that were being perfect little monsters, and their names . . . well, Lord Boromir did not need to learn their names; after all, weren't the elves supposed to be remedying the situation?
After a while, Boromir decided to investigate the situation further. As soon as he entered the main hall, he saw that four elves had been knocked unconscious, and were lying in a heap near some suits of armor. He then espied two elves hanging upside-down from the ceiling, also unconscious. Food from the kitchens had been scattered all across the floor, and wine had collected into large pools spanning across the hall. After a few minutes, Lord Boromir saw Lord Elrond, Lord Glorifindel, and Lord Erestor, huddled together, shivering like rabbits caught in a spotlight.
Lord Boromir decided to evacuate the premises immediately. Before he could back out of the hall, two rather large badgers with brown fur ran straight into him, knocking him to the ground. Upon closer inspection, however, Boromir discovered that the badgers, were in fact, the devious little buggers named "hobbits." Now, Lord Boromir feared for his life. The hobbits looked down at Boromir, and he stared fearfully up at them.
"Er . . . sorry about that . . . listen, d'you know where they keep the ale?" Pippin asked nervously.
Boromir was busy looking for a door close by that could be used as an escape route.
Pippin looked questioningly over at Merry, who merely shrugged his shoulders, and decided to get up off of Boromir. As Pippin followed suit, Boromir crawled away from them as fast as possible. Merry then raised his eyebrows at Pippin, fearing for the strange man's sanity. Boromir then ran from the hall with all haste. Merry and Pippin walked calmly out of the hall, both sparing a glance for the elvish lords, who were following every move that Merry and Pippin made.
Thus ended the great hobbit rampage of Imladris. No one could count the causalities5, and the scars it left on the minds of the victims6. It was because of this tragedy that the elves of Rivendell fled from Middle-Earth, never to return; soon, the word spread to Lothlorien and Mirkwood, and soon, those elves abandoned their homes, for fear of the hobbits' unquenchable hunger. Thus, the hobbits were the reason that the elves sought the Undying Lands.
1: Instead of stomachs, they have black holes.
2: Excluding: Men, Dwarves, Elves, Istari, Maiar, Orcs, Trolls, Wargs, Other Mystical Beings, Etc.
3: The kind of mischief that lands the victim in a rubber room within an insane asylum.
4: They don't do anything. I mean it. They sit around, and do nothing.
5: As there had been none.
6: Again, there were none.