Oh, I'm sure I have it saved somewhere, but your point is apt: if all you remember is the general concept, but none of the key phrases used, nor a specific enough timeframe, when you've been saving things about wearable computing for fifteen years (as I have), how do you find it? I don't know that that's a solved problem yet.
At least, it would only be fifteen years of personal saved items to go through, instead of the entire internet.
Would life-logging help us find this essay or would the essay still be tricky to re-discover?
(Frustratingly, Wikipedia "Lists of X" is in fact "Lists of X where each item on the list must have a Wikipedia article". That's probably great in some respects, but it makes for a lousy comprehensive list.)