As long as you understand the concepts and how the process flows, you should be good to go.  One thing I really want to emphasize - do not memorize.  Understand the concepts, create a scenario in your mind, and apply the concepts in the PMBoK.   If you are a PM practioner, do not insist what's practical in your head - stick with the PMI.org concepts. 

1)  Key concept: Do what's good for 1) the customer 2) then your organization.