That's the same sort of thing I said when I bought my first 40MB drive back in 1989. I figured I'd never come close to filling that thing up.
But 80GB is still hard to grow out of, unless you use it for editing video clips.
I've had a 60 gig drive for a year and a half. I have thousands of 1mb photos on it, taking no discernable space. I have ripped about a dozen CDs to WAV files for building mix CDs, and still haven't filled half of it.
Video is about the only thing that could fill it quickly.