I often prepare papers for conferences with an upper limit on the number of pages. I spend a lot of time thinking what words and characters to delete in order to make the paper fit in the page limit.
Recently, I run into an interesting and paradoxical phoenomenon: I remove some words, and the number of pages increases! As an example: I have a two-column paper. I remove two words from the top of column #2 at page #1. As a result, LaTeX takes the last line from column #1 and puts it on top of column #2. Now, the last line of column #2 is pushed to page #2, and so on, and this leads to page overflow.
It is very difficult to create a minimal working example since this behavior doesn't make much sense to me. So before I spend time to create an MWE, I will be happy to know if this behavior is known.