As was pointed out by someone else yesterday, when Jesus said, I am the door, I am the light, I am the good shepherd, I am the true vine, was he literally those objects, or were they metaphors, and how could you distinguish between them?
Actually He is a shepherd, as to the other stuff well where in the Bible did he point out a door on a building, and say I am that Door, all how wish to be saved should enter? Or where in the Bible did He point out a vine along the road, and say I am that Vine?
In a sense He is all these, however only the Eucharist did he fully explain.