Depending on where you live, street numbering may not be something you’ve given a lot of thought to. In Canada, and in many other places in the world, the convention is usually to start on one end of the street and count up – with even numbers on one side and odd numbers on the other.
In many cities in the US, they’re even more rational. The streets themselves are numbered and the addresses indicate location. For example in Philadelphia, where I used to live, if you were going to let’s say 1750 Walnut Street, you would know that it’s between the cross streets of 17th Street and 18th Street. It’s a kind of hyper-rational approach, which lets you know precisely the number of blocks you need to go to get to your destination.
But not all countries and cities are this rational.
According to this Economist article – which a friend of mine forwarded me over the weekend – Costa Rica actually had no street numbering system until about 2012. Which means that directions were all based on landmarks: “100 metres south of the McDonald’s.” It seems almost hard to believe. But I guess that’s why ¼ of all mail was getting lost.