Not knowing if the text went through
This can go on for hours or days or weeks. You know the guy got back from traveling abroad on the 14th. You sent him a text on the 14th at nighttime. You’ve heard nothing back. Maybe his plane was still in the air when you sent it? Maybe he’s out there, wondering why you haven’t reached out? Maybe if you do reach out again, he’ll think you’re insane! Aaaaargh!