Flash not clearing after a request?

We all know “The Flash” to be a very useful tool in almost every application we write. What does “The Flash” actually do? The flash provides a way to pass temporary objects between actions. Anything you place in the flash will be exposed to the very next action and then cleared out. Well, that’s all nice, but what if you notice that your flash is not cleared, and is shown in one or more subsequent requests as well?