OK, maybe that example is too extreme, not general enough. Let's say you're a secretary, and the entire morning has been spent preparing a memo which includes budget and other important information. Let's say the memo is due by five p.m. to the VP and your boss wants it finished ASAP after she reviews it during lunch. Let's say probably not, and you should hope your resume isn't on that same disk. Backing up data on a PC is analogous to wearing a seat belt, brushing and flossing one's teeth, and getting a car tuned up and oil changed.
Prevention is the key.
OK, I am going to assume you're convinced. The next questions should be what, when, where, and how. The easiest way to keep an emergency copy of these files is to copy them to a boot disk. A great way to protect against data loss on a hard drive is to know where the data is in the first place. It is surprising how many people lose information just because they do not even know where they keep it.