Victoria Song writes: “When Gmail launched with a goofy press release 20 years ago, many assumed it was a hoax. But soon, invites to Gmail’s very real beta started going out—and they became a must-have for a certain kind of in-the-know tech fan. It now has an estimated 1.2 billion users, and it’s a practical necessity to do anything online. But I don’t know anyone who’s champing at the bit to open up Gmail. In another 20 years, will Gmail still be central to our lives?”