Well, Like you saw, it's the *data* that takes the space. I got by with a 40mB HD on my Amiga for years. Heck, I even used a RAD: disk without a HD at all. Even now, it only has a 500mB internal and a 1 gig external, practically empty most of the time.
But if I put my data over there, I could probably fill up most of a 100GB drive. Music files, old radio shows in mp3, pictures, animations, video captures, all those scanned in Amiga magazines :-) saved web pages... it builds up quickly. Now, I could (and do) keep that stuff on CDR, but it's no substitute to having it all accessible in one place.
Jim