You and your friends keep "streaks" — sending each other a message every single day to keep a number going. Miss a day and the streak resets to zero. You've got streaks going with loads of people now, some of them you barely talk to otherwise. It's become a job. On busy days, on holidays, even when you feel ill, you have to fire off messages to everyone just to keep the numbers alive. If you forget, people get upset, like you've let them down. You're not even sure you enjoy it anymore — but the thought of losing a long streak feels weirdly awful. The numbers have started running you.