Finding my way around in Tokyo

Why don't they have street signs in Japan? I look to my left, my right and I see...skyscrapers, skyscrapers, and MORE skyscrapers. BUT no street signs.

I think people over here find their way around by remembering landmarks....my friend Santi once said the same thing to me. He was amazed that people gave directions like the following "When you see the McDonald's next to the Mitsubishi Bank, then turn left, keep going until you see Kinokuniya, then turn right into a narrow path once you pass the Starbuck's Coffee...etc. etc." Uhh...confusing?

For those accustomed to this method of finding their way around, it probably works fine...but I seem to still look for addresses, which isn't a smart way to find your way around in Tokyo. After many many episodes of getting lost, I've figured out that they have little metal plates with the zipcode-like information on the electric poles....so now whenever I get lost, I walk around looking for power poles and inch my way closer to the vicinity of where I'm heading. It works pretty well =).