To prepare, Terry used TestiT, a written testing system created by NetMasterClass.
Their written test questions focused Terry on the areas of technology that he needed to study.
Terry didn't take the approach of studying to the test - he took the approach of learning the technology that was covered by the questions.
When Terry encountered a question that he answered incorrectly, he read their solution summmary and used their reference links to read up on the technology:
Are YOU a CCIE whose current job is far removed from daily operations, if so, how did YOU study to earn your CCIE recertification?