PSD files

I have an unusual question... but I just kind of wanted to get some general opinions. I think I'm kind of paranoid about changing an icon or in case I lose it or something, so I always keep the original PSD file, which of course is pretty big in file size. So it would probably be better for my computer and better for organization for me to delete them, but for pretty much ALL my icons, I still have the original PSD as well as the jpg version... eh... do you guys think this is just silly, or does anyone else do this?