Mysteries of Faith (or why you should not attempt to explain Transubstantiation to a four-year-old)

We ended up in the front pew today as someone else was sitting in our usual spot when we arrived just before Mass started. The boys were extremely well behaved (a welcome change from last week!) and Daniel was paying more attention than ever before--kneeling when I was, standing when I was, etc. In the front pew, you get to watch the entire congregation file past for Communion, which gave Daniel some time to think.

D: Mom, is that a cookie?
M: No
D: What is it?
M: Bread
D: What kind of bread?
M: Well, remember when Fr. John was holding it up high and saying a prayer?
D: Yeah
M: Well, when he says that prayer, the bread turns into Jesus.
D: The bread is Jesus?
M: Yes
D: (ponders for two or three beats) Well, what part did you get? Head? Middle? Feet?

Um....yeah...so, not exactly an easy explanation there. We ended up with "the bread is a symbol that reminds us that we have Jesus in our hearts." Which led to, "Jesus in our heart is what helps us make good choices." Which led to, "You mean when I make a bad choice Jesus leaves my heart?" And then, "Jesus is always in your heart. He helps you know when your choice is good or bad."