It can also be confusing to read. If you have, say, some insights into metallurgy and some fascinating ideas about chia pets, tossing them together into a single page is just silly. Make each of your pages stand on its own by dedicating a single page for each topic. In the long run, your readers will be eternally thankful. Well, lengthy web pages have lots of disadvantages.
Large files can take forever to load, especially visitors accessing the web from a slow link.
If loading the page takes too long, most people are more likely to abandon you and head somewhere else. Nobody likes scrolling through endless screens of text. Pages with more than three or four screenfuls of text are hard to navigate and tend to be confusing to the reader. Some studies show that many web surfers don't like to scroll at all. They want to see one screenful and then move on.