I have terrible handwriting. In top of that problem, I sometimes use too much pressure. And I tend to leave the pen on the paper while I think of what I’m going to write. With a fountain pen, too much pressure means more ink released, which leaves ugly blotches that readily soaks through a few pages.
So not only is the first page ruined by my initially ugly handwriting, the succeeding pages are further ruined with the blotches of ink that soaked through.