loading controllers when navigating through screens

Im currently using directives in my ionic app, there directives are normally bind to a angular controller. So my problem is, when I navigate through the app, my controllers are not loading (loads for the first time) and hence I cannot setup some initial values.

Following is an example

1. I navigate to users screen/page
2. users controller loads (When I check with chrome dev tools)
3. I navigate to home screen
4. I navigate back to users screen

** At this point I expect users controller to load again, to setup my initial values. but its not happening

I'm not sure if this is the default behavior or am I missing something.

I hope I put the question clear, thanks in advance