Ever since alge­bra was invented—and prob­a­bly earlier—letters have been made to coex­ist with math­e­mat­i­cal con­cepts. As a child I always felt that this was some kind of abom­i­na­tion that was only tol­er­ated because we already rec­og­nized let­ters as abstract sym­bols so appro­pri­at­ing them as des­ig­na­tions or vari­ables made sense. From that stand­point. For me, the “num­ber x” was mak­ing sweet love to the “num­ber y” so that the “num­ber c” could be born. The creepy part? That the let­ter x could turn out to be exactly the same as let­ter y. OH! See what I did there? I just turned a per­fectly nor­mal topic about using let­ters in math and made it creepy and wrong. What can I say? It’s a talent.