The hard start is the point

Some weeks into the new thing, the honeymoon's gone and the difficulty is plain. The work is harder than the old work, or harder than you remembered work being. You start to wonder if you made a mistake — if the smooth competence you had before was proof you belonged there, and this struggle is proof you don't belong here. That reading has it backward.

Epictetus put it flatly: "It is difficulties that show what men are" (Discourses 1.24, Oldfather). Then his image: when something hard lands, remember that God, like a trainer, has matched you with a rugged young opponent — not to break you, but so that you may become an Olympic victor. A trainer who only ever paired you with someone weaker would be cheating you of the thing you came for.

The nurse on a tougher ward, the tradesman on an unfamiliar system, the manager handed the unit nobody could fix — the strain they feel isn't the sign they're failing. It's the resistance you can only grow against. Easy work leaves you exactly the size you already were.

This is the heart of starting over: you chose the harder match on purpose. Don't resent the rugged opponent. He's why you're here.