A while back a mac user group newsletter had a joke that ran something like this:

What if your car behaved like a PC. Stopped working or froze or crashed unpredictably. Needed to be restarted in mid-task. Had a back seat driver like that gizmo that says "I see you are trying to write a letter, would you like help" popping up all the time. And so forth and so forth. That vehicle would not last on the road--or be allowed there.

Macs rarely rarely have those problems.... and the OS X systems are set up so if there is any sort of problem, your work is saved in a memory bubble and can be retrieved.