The joys of email 

In Tim Ferriss‘ most recent post he quotes Don Knuth who, in 1990, stated:

“Email is a wonderful thing for people whose role in life is to be on top of things. But not for me; my role is to be on the bottom of things. What I do takes long hours of studying and uninterruptible concentration. I try to learn certain areas of computer science exhaustively; then I try to digest that knowledge into a form that is accessible to people who don’t have time for such study.”

Don Knuth

Knuth quotes Umberto Eco, who told the New Yorker (presumably before 1990):

“I don’t even have an e-mail address. I have reached an age where my main purpose is not to receive messages.”

Umberto Eco

There are many reasons you wouldn’t be able to get away without an email address in this day and age. But what’s the equivalent of something that it’s current possible to opt-out of, that is a time-suck? Social media? Instant messaging apps?