I will elaborate this a bit further. That's a damn good point Boneski.
IRL each a/c has a service life accumulated in flight hours- time limited components, engines, propellers, gearboxes, APUs etc. As the operation progresses the wear of gears and bearings increases depending on how you operate your a/c and it's systems. A component could fail if you exceed it's operation limits. That's something that none simulator has implemented yet- a system that records the total time in flight and ground. And if you have ability to monitor it you should be more careful when your a/c or engine gets close to the TBO deadline when you pull 9G's sustained or keep the burner on for ages.
You may say that this is a flight, not a maintenance simulator but IRL flight and maintenance come hand in hand. You can not make a good flight without proper maintenance. And I don't mean a crew of mechanics dissassebling your a/c in the hangar. But a wear factor that progresses with the time that could randomly (with increasing probaility) cause a component to fail would add a great realism. In LO we have pilot wear, pulling high G for a long time make your pilot loose consciousness for few seconds but that's a helluva stress for the a/c as well.
Not to mention helicopters. Do you know how many times I've found steel chips on the Ka-32's gearbox's chip detectors? Hell I even survived an emergency landing last year after the right free-wheel drive colapsed due to lubrication failure (oil nozzle contamination).
Or the MiG-29's RD-33 engine that was a subject of discussion recently- the first series has a TBO of... 300 hours. And quiet often engines have been sent for overhaul before reaching this number. Main reasons- cumbustion chamber wall burns, turbine stator and rotor blades burns, fuel manifold support elements cracks. If there was a wear factor (flight hours and modes of operation accumulation) the F-15 pilots wouldn't complain so much that their plane is underpowered while the MiG drivers would switch to another a/c after they've had a random engine failure like blade destruction for example :D