Continued form Why is it that "eye" must go.
In keeping with the contiguous clue theme, the last clue defines the next clue. So I've done it tired supports the why is it that eye must go, because when we are tired, we try to keep our eyes open just like Mr. Fenn did over Philly in the T-33. Now the cool part, the instructions "and now I am weak," which many assume that his body is weak. But he told us that nouns in the poem are important. What if weak is a noun?
A weak in the noun sense, is actually the tip of the sword, so the instructions to the searcher is to strike out from the eye to the tip of the sword and make a slash or so to speak. Now it makes much more sense as to why Mr. Fenn said he drew that poem.
Where is the tip of the sword? Well since the big picture clearly shows Excalibur (sword in the stone), we go to the Final Two Clues that put the "X" on the map.