He did not live there. If I go visit the fiance of my father, I am not a neighborhood guy. I am a visitor. Possibly even a stranger, if those visits are not regular in nature.
"I'm having some difficulty getting my mind around the fact this very long term Neighborhood Watch guy didn't know the address where he was located."
You may have an even harder time after being beaten in the face like Zimmerman was. I'd imagine it can be somewhat disorienting.
BTW, where's all that blood you'd have from a real up close and personal shooting?
Bet the FBI forensics people can tell how far away Zimmerman was when he shot Martin. 10 feet maybe, 15 feet? 30 feet? What's your guess?
Certainly more than right on top of him.