It’s a Sunday evening, and I’m staring at my phone, thumb hovering over a green chat icon. A friend I haven’t met in three years, someone who once knew my every mood before I could even name it, has sent me a meme. I ‘react’ with a laughing emoji, the digital equivalent of a polite nod. The last time we had an actual conversation, the Prime Minister was still in his first term. We have not fought, nor disagreed; we have simply let the friendship drift into that strange cloud-storage zone where it still exists, but no longer runs in real time.It happens slowly.