You send a message at 2:47 PM. They read it at 2:49 PM. Now your phone is a bomb that might explode at any second—you're checking it every twelve minutes like it's a lottery ticket, refreshing your entire personality in case the problem is you. By 5:50 PM you've convinced yourself they've died, moved countries, or discovered you're actually terrible and are currently telling everyone. Then they reply "lol sorry I was busy" with no explanation of what could possibly matter more than your medium-length text about a vaguely funny thing that happened.