One of the things I love the most about Japan is visiting the different temples and shrines, but even I've been templed-out before. That was after a week of going at it pretty hard, mind you, but still...
It definitely depends on the person. I've spoken to tourists who were templed out after the first couple. It took me until my third visit to Japan and a rough flight on the way there (as in I couldn't sleep, so arrived in Tokyo with a very short temper) for me to hit the templed-out stage, and it lasted a whole day
