You have spent a lot of time on your computer, and created a lot of files. Unlike your programs, they are unique, you created them. What happens to them if something happens to your computer?
One of today's modern tragedies is loosing one's computer data. All those months, or even years of work - gone! Unfortunately, it's not something many people think about until it's too late.
So what can you do?
Remember your operating system and programs can be reloaded from their original disks. Yes, it can be a lot of work to set your computer back up, but these days backing up an entire system can be very time-consuming. At least focus on any data that is both important and irreplaceable!