To reply to you and DHK, you have to read the Jn 6 Bread of Life Discourse (a) in its entirety and (b) in conjunction with the Words of Institution in the Synoptic Gospels: "This is My Body, this is My Blood". So, when read in tandem with "I am the Bread of Life", the meaning is clear: this is not merely an "I am...the Gate, the Door etc" -type statement, this is also a "This is..." statement. Now, Memorialists say that this "This is..." statement is no different to them saying "This is my wife" when referring to a photo of her ie: it doesn't mean it's actually her. But there is one crucial difference: they are not Jesus. Consider Who He is: the Second Person of the Trinity, the Word of God, there at the beginning in Gen 1:1. We see here and elsewhere that what He says effects a change in the fabric of reality, whether that's saying "Let there be light" in Genesis, or in the Gospels statements like "Your sins are forgiven" and "Your faith has made you well". As it is there, so it is here: "This is My Body, this is My Blood."Because the RCC hierarchy has decreed that one is a metaphor and the other is not, and that no RC is permitted to see a metaphor where the RCC has decreed that one does not exist.
I can't see how any sane person with an ounce of common sense can draw a non-Realist conclusion from the above, unless they are swayed more by the prejudices of their own traditions (of men) than they are by the plain words of Scripture. That doesn't mean of course (to answer Bob's point) that one automatically becomes Catholic, as there are other churches who subscribe to a Realist position about Communion, but it does mean that in all conscience one cannot remain a non-Realist/ Memorialist...