Attention Residue — A Thirty-Second Reply, a Twenty-Minute Price

University of Minnesota professor Sophie Leroy introduced **attention residue** in 2009: when you switch from task A to task B, A's cognitive residue follows you — your surface behavior is on B, but part of your attention is still stuck on A.

For someone mid-work (cutting, doing nails, mixing color), this means:

**The real cost of one reply = the 30-second message + several minutes of focus reconstruction afterward.**

And focus reconstruction costs more than time. Craft quality runs on focus — dye mixing ratios, cutting-angle judgment, massage pressure control. An afternoon interrupted twenty times isn't just slower by twenty thirty-seconds; the entire afternoon's craft quality soaks in diluted focus.

Twenty 'quick replies' a day: your real cost isn't ten minutes. **It's a whole afternoon's quality of work.**