I don't know why but sandwiches from somewhere always seem to taste better to me than ones I make at home, even if I copy it exactly. I don't know if it's psychological or what, but I'm always at least 10% disappointed with my homemade sandwiches.
I could have fresh crunchy lettuce, fancy mustard, premium meats, sprinkles or celery salt, fresh onion, whatever - it still doesn't match some sandwich I get out and about. I don't get it.