The clutch disk failure is one of the inevitable dangers you face to trust a human being doing a job usually designated machines. But even if you are perfectly gentle with the clutch, anyway it will wear over time. Take comfort yourself with the fact that it is a small price to pay to drive your car without computers nannies thinking for you.
Normal wear and tear
As the brake pads, all clutches wear out over time. Even if slip clutch as little as possible, it is not likely that the friction disc lasts the life of the engine or transmission without the need to replace at some point. The springs of the pressure plate holding the clutch disc on the flywheel eventually weaken and cause clutch slippage, and you can probably have a release bearing failure or clutch cylinder at some point.
Overheating clutch
The clutch material as the material of the brake pads in more ways than one, the principal of which is that even an event overheating can permanently glazing material surface. Then, the clutch disc loses its ability to grip the wheel and develops a tendency to slip. The failure is progressive from there; each time the clutch slips, it gets a little worse, until it stops working at all. You may be able to postpone clutch failure for a time after a severe overheating, but will never be the same until you replace the disk.
Water in the clutch
A wet clutch is not necessarily ruined as long as you give it time to dry, but it can be if you drive the car before you do. Water enters the clutch material, which in turn is something like a resin impregnated cork. Once wetted, the clutch loses some of its ability to grip the steering wheel begins to slip, generating heat and converting the water into steam impregnated. The steam expands in the pores of the friction material, literally tearing the strip material from the inside like an egg in a microwave.
Oil on the clutch
This is a fairly common error and old engines and transmissions, and occurs as a result of a fault in the engine rear main seal or the front of the transmission. Hot oil viscosity has little water, which means that penetrates the clutch disc as water. But unlike water, the oil in the clutch was not dry after a while it will stay there for years, waiting for you to try sending power through the clutch and transmission. Once you do, the clutch slips, overheats and burns.