Of course it doesn't have to be a 50mm, but it's something to consider.
No way I'm shooting every day for even a week just hanging around my home town...
I had that sort of sense at one time too. I've worked at seeing things differently and have found plenty to shoot. It does largely depend on what you like to shoot, and for some things you need to be in a place with lots of fodder.
I do like the idea of imposing limitations though, even for a short time. It can create new ways of looking at the world, and new ways of 1using the tools at hand; gear, light etc.