As somebody who has used computers for a long time, I have had about 4 hard drives die on me during my life. Some were external, some were internal. I've developed a paranoia about it. I always imagine my computer getting bumped the wrong way while writing data, writing it to the wrong sector of the drive or having a head crash, and then everything going to hell. I look forward to getting a machine with a solid-state drive once the prices come down more, but in the meantime I was wondering: is this a realistic phobia to have? I don't understand the physics of a hard drive, so maybe it's a stupid thing to ask, but I would like some education on this issue. So: How is it that drive head being "one two-thousandth of the thickness of a human hair" can move back and forth (how many times per second?) across a platter spinning at 5400rpm and read/write every 1 and 0 with complete accuracy, often many years at a time without breaking down?!