Symptoms: You’re worse than a Tiger Mom when it comes to seeing that little "Percent of Game Completed" stat on your game menu. Anything less than 100% means complete failure, punishable by neurotic self flagellation. You’ll navigate back to the most insignificant, inane side mission—that ^%^@# one where you have to jump on rocks and catch a butterfly—to boost that 99.6% completion mark. The only time that it was SORT of worth it was in FFX-2.
IRL: Actually, this would be a perfect "habit" to have in real life. Striving for a 100% completion rate would entail pursuing all of your life goals: getting your MBA, traveling to San Sebastian, opening your own graphic design firm, hooking up with a half Puerto Rican dime, meeting Lou Ferrigno, attaining a pair of signed PE Jordan XI’s…so if you already are this neurotic, be glad. The only downside? You'll probably end up alone.