dealing with dupes
Anybody that uses a particular computer long enough is going to end up with dupes; this is anything on your box that you have more than one instance of. If you bookmark a web site twice in the same browser, that's a dupe. If you downloaded a funny photo, then downloaded it again because you forgot you downloaded it before, that's a dupe. You get the idea.
It's important to note that dupes are not the same as backups. Backups are important but dupes are worthless.
You encounter dupes at their worst when transferring data from one computer to another. Over the course of 10 years you could go through as many as 3 to 5 computers. Each time you get a new computer box, you copy your old crap to your new box. And the way everyone does it is the same. Nobody carefully picks which files to copy; they just copy everything because it's easier. I usually do the same.
With the arrival of my new optical drive coming soon, I decided to organize as much of the old crap as possible to minimize dupes, and wow did I find a lot of duplicated crap. Tons of it. Apps that I copied/downloaded/whatever 5+ times, the same images buried in subfolders in 10 different RAR files, etc. The whole thing was a mess.
If you're wondering why I'm even bothering doing this, the answer is simple. Less dupes means less data that needs to be burned to disc and less time needed to get the job done. I estimate that I cut out at least 3 to 5 DVD's of worthless data, and in addition RAR'd anything I could to cut down file sizes even more.
How does one accumulate several gigs of useless duped data? Well, it's not an overnight thing. When you have the space you just dump everything into the download folder and pay it no mind. Then one day you actually go in the folder and you're like "WHOA.. time to clean this crap up." That's how it usually works. 🙂