According to DDism, satisfaction in life is measured by general happiness, not how many AAs you got.
If you are not in "probation" status and having a passing grade (>=DD), do not take any course again and again to increase GPA.
DDists attend lectures to become a master in their profession. They never memorize the "Past Exam Questions" for GPA. However, that does not mean "Past Exam Questions" are useless. They could be useful while grasping the topic.
According to DDism, you should also improve your non-acedemic skills.
By making you qualified and productive, DDism will make you feel satisfied.