What it means
A firm little nudge that means calm down, stop spiralling, and get yourself back in one piece. You say it when someone's flustered, upset, or seconds away from a full wobble and needs to breathe, focus, and sort themselves out.
Usage examples
"I know the news was a shock, but pull yourself together, we have got a flight to catch and a plan to make."
"Come on, pull yourself together, the interview is in five minutes."
"She took a deep breath and pulled herself together before going on stage."
"Mate, pull yourself together, it's only a flat tyre, not the end of civilisation."
"He was proper panicking at the till, then took a breath and pulled himself together."
Where it comes from
This phrase has been around in English since at least the late 19th century. It builds on the old image of a person emotionally coming apart, then pulling the scattered self back into order. The idea is simple and vivid: regain control, composure, and a bit of backbone when you're slipping.