Have you ever noticed that all of a sudden Photoshop is just acting wacky? Maybe the application is crashing frequently or fonts are missing. If you're suddenly experiencing performance issues within Photoshop, it might be due to a corrupt preference file. Luckily, even though preference files corrupt often, they're simple to delete, and will rebuild themselves the next time you launch the application.
After you've created multiple text layers, you may decide that you want to change the size, color, or font of all the text layers. You could select and highlight each layer of text and manually change its font attributes one by one, but who has time or the patience anymore?