That low hum you feel after helping again isn't kindness fatigue. It's resentment, telling you the boundary went missing.

The thought behind it

Once a vague dread has a name it stops being weather and starts being a decision. That is what this sentence does. Quiet Power is the strength that leaves no evidence — the no, the pause, the purchase that never happened. The weight sits on “resentment” — the one word you cannot swap out without losing the whole point.