Some of our favorite fun facts? According to The New York Times, early forms of deodorant can be traced all the way back to the ancient Egyptians, and the first trademarked deodorant surfaced in 1888. And, there's actually a downfall to brand loyalty: You can become immune to your deodorant. So, add some variety to your routine and switch brands every six months to prevent this from happening.
Also, much to the dismay of deodorant companies everywhere, not everyone actually needs it. Some people simply lack the chemical that produces underarm odor. Head over to The Huffington Post to find out more surprising facts!