Every year a commercial pilot must go through a testing process to evaluate her skills and abilities to handle the aircraft and any emergencies that could arise, the test is called a "Check Ride". I don't know too many pilots who look forward to their check ride, I usually manage to fly my absolute WORST during these tests. Yet, I believe that the check ride is a valuable tool and quite necessary for pilots to stay on top of their "game" so to speak.
The same concept applies to the airplane itself. Every year an airplane is inspected for safety's sake. My husband is an aircraft mechanic and looks at a lot of airplanes during their "annual" inspection. He finds things that need repair or tuning up and either does the work himself or directs the aircraft owner to do it before he signs the airplane back into service.
I am about ready to fly from Alaska to Tucson, Arizona for the Mrs. America pageant and I feel like I've put myself through a check ride and an annual all at once in a matter of a few short weeks! I have evaluated my abilities, tested my knowledge, "tuned up" my physique and repaired anything that came up short or out of whack. WHEW. Am I there yet??? I'm ready to go. And for the record, my husband has had fun doing all of the inspections!