What if we trained mental capacity the same way we train physical fitness: through reps, metrics, and practice? It’s the first week of January, and you’re already drowning in Slack messages. You told yourself this year would be different, that you’d set boundaries and stop overcommitting. But here you are, saying yes to another meeting you don’t have time for, staying late to fix something that could wait, feeling that familiar knot in your stomach every Sunday night.