Before coming to IIM A, I had this perception that open book exams are somehow "softer" and simpler to crack. Only after 2 Slots(4 more to go!) realized(after some eyeopenng papers) that they reflect the way we work in the real world.
Think about it. When faced wth a situation at work will you avoid opening any reference books/notes etc or would you rely only on what you learnt last in college. The former obviously is what most people would do.
The skills sets needed to mug are far different from the skill sets needed to refer to/locate information in the Googled world. And that is what open book exams teach you.