Nature/Cause of the weariness of Eldar in the Third Age

[Legate of Amon Lanc]

Originally Posted by Nogrod

That's why those elves dwelling in the West had no such problems, living in the platonic world of perfectness as they were. And because of that gap between men and the elves we men can never really understand the bliss of an ever-unchanging world the elves might long for - and therefore the only meaning given to us humans is, like Gandalf says "deciding what to do with the time that is given to us".

That's exactly it. And that's why the Elves were so overwhelmed with the sight of Men with their ridiculously short lives doing feats that equaled or sometimes surpassed those of the immortal Elves - just because of this. They are given such a short live in the Circles of the World, but that can serve as a motivation, and - okay, here I would disagree with Eönwë - it can lead them to actually care more of their actions, and of their effect in the future. If they do care, then they face only one problem - that of their short life, which means little experience, and being prone to do all sorts of stupid things based on miscalculations (like Isildur not destroying the Ring, being so full of himself).