When you're writing, what do you do to emphasize a particularly important idea to your readers? It's sloppy writing to explicitly state that you're making a really important point. Additionally, you can't capitalize, bold or make your text larger to set it apart. The solution to show emphasis is to italicize your text (which you can do with any work processing software with the I icon. When you stress something with italics, it doesn't need to be a complete sentence, rather you can merely be stressing the importance of one or two words. Indeed, sometimes when you might be tempted to point out the amazing quality of a fact with an exclamation point, italicization is a much better tool to use. For example take this hypothetical "fact":
"My friend taught himself how to read over ten thousand words per minute!"
"My friend taught himself how to read over ten thousand words per minute."
Other times that italics should be used when writing include titles of books, plays or movies or foreign words that have not come into common usage in the English language (for example "laissez-faire" and "entrepreneur" are both French words, but they have been completely integrated with the English language). A Tale of Two Cities by Charles Dickens takes place during the French Revolution, the era of Liberté, Égalité, Fraternité.