Quote from Janet in The Eternal Shriek
Chidi: Uh, Janet, how many "Janets" have there been? Janet: There have been 25 generations of Janet. Each new update of Janet gains more wisdom and social abilities. Fun fact... the first Janet had a click wheel. Chidi: So it's like aging for a human? You're... you're growing up? Janet: That's how I like to think of it, Chidi. I can't eat, so every time there's a new version of Janet, I like to take a piece of birthday cake and smash it around where my mouth is.