This repo showcases hat if you forget a var keyword in Node.js, it'll leak the variable into a global variable, accessible from other files and modules too! Just like it would in the browser!
Why did I even bother doing this? I write CoffeeScript, which ensures all variables are locally scoped, so I never realised this behavour actually occurs within node, so was surprised when it did. Perhaps my fault? Maybe. But at least, using CoffeeScript means I never have to worry about this, perhaps time to give CoffeeScript a go?
node one.js