Getting edgy on seeing this. I say you must be. Extending hard disk drive life is certainly a major concern nowadays. Have you ever faced hard disk drive failures when your tonnes of data is just there in front of your eyes and is just not there. Hard drive is lying in front of your eyes but you cant extract any data out of that. If you have not, then I would say you have been very lucky. Today with so much reliance of data in electronic forms, people would get crazy if they lose their data and have not taken any steps to back-up.
Like any electronic device, Hard Drive where we store our precious data also has some lifetime. The lifetime varies depending upon under which condition the Hard Drive is being used. Temperature, Humidity, dust etc. all these parameters affect the lifetime of a hard drive. Though a hard drive lasts on an average 5-10 years but it would be better if one is cautious after the lifetime of 3-5 years. Every hard drive gives early warning signs.