Marshall names four forces that fight you whenever you try to install a new or better way of doing things: 1. **Entrainment** — your default is simply whatever you've been doing lately; the automatic response to a stimulus is whatever your past responses were (see [[Entrainment]]). 2. **Homeostasis** — the body self-regulates and resists change in its biochemistry, even change that's good long-term. A sustained caloric deficit triggers pressure to eat; quitting caffeine leaves you tired and irritable while the body re-balances. 3. **The neuron thing** — patterns you've repeated get encoded into efficient neural paths that never really disappear. Unused, they go dormant, not gone; return to the behavior and "it's like riding a bike — you never forget." One drink can send a recovered alcoholic back down the whole chute. 4. **"Ambitious Person Syndrome"** — the same neurotic drive that powers high achievers can, redirected, power self-destruction (see [[Ambitious Person Syndrome]]). The point is not despair but accounting: change feels hard because four real forces oppose it, so willpower-in-the-moment is outgunned. But the flip side, Marshall stresses, is that all four can be turned to *work for you* once a good pattern is established — the encoded paths, the homeostatic pull, and the drive all then reinforce the ascent. --- *Source: [[Book Inventory/Progression|Progression]] (Sebastian Marshall, 2016) — Upstream Effects #4 — Firebreaks and Rapid Repairs*