Maybe it's interesting because the phrase "per se," something we already borrowed from Latin, is inside of "ampersand," which I certainly did not know.Despite appearances, the history of ampersand owes nothing to amp or sand. The familiar character & derives from a symbol that was used in place of the Latin word et, which also means "and." In the late Middle Ages, single letters used as words—words like I—were, when spelled, incorporated into a phrase that clarified that they were in fact individual words. For I the phrase was I per se, I, which in Latin means "I by itself (is the word) I." In early lists of the alphabet, Z was followed by the symbol &, which was rendered & per se, and, meaning "& by itself (is the word) and." Over the years, that phrase (which when spoken aloud was pronounced "and per se and") was shortened by English speakers to ampersand.
It's also interesting because I learned that what comes after Z in the alphabet was, at one time, ampersand. Which is hilarious.
Actually the third reason it's interesting because it was once common to actually clarify that a letter (such as I) was actually a word.