There’s strong evidence that chewing gum improves working memory, episodic memory and speed of perception. Why this is the case is not understood.
There is a strictly enforced ban on chewing gum in Singapore that has been in effect for decades. Bringing chewing gum into the country even for personal use is illegal.
William Wrigley, Jr. sold soaps in 1891, offering baking powder as incentive to buyers. The baking powder proved to be more popular, so he started selling it, offering gum as incentive. But the gum proved to be even more popular, so he started selling them. In 1893, Juicy Fruit debuted.