The plateau is not a pause, it is the new normal

Improvement stops being automatic long before it stops being possible.

A plateau feels like a malfunction. The same hours go in and nothing comes out, and the natural reading is that something has broken: the method, the teacher, the tools, the person. Usually nothing has broken. What has changed is that the easy gains have been taken. Early progress comes from removing gross errors, and gross errors are plentiful and obvious at the start. Once they are gone, further improvement has to come from finer and finer distinctions, each of which takes longer to notice, longer to correct and produces a smaller visible change. The curve flattens because the work has changed shape, not because the effort has failed.

What makes the plateau dangerous is that ordinary practice keeps it in place. Repeating what you already do well maintains the level and reinforces every habit that produced it, including the faults. A person can spend years on a plateau working conscientiously and finish exactly where they began, only more fluent at their own errors. Moving off it usually means going backwards first: dismantling something that already worked, tolerating a period of playing or cooking or building worse than you did last month, and doing that without any guarantee that the new way is better. Most people, reasonably, decline.

The other reading is that a plateau is where the skill consolidates. Something learned at speed has to be worked into the body, and that takes uneventful time. From the inside those two states look identical: the long stall and the quiet settling. The only reliable way to tell them apart is external. Someone who can see what you cannot will say either that you are grinding a fault deeper or that the thing is bedding in. Without that voice, a practitioner on a plateau is guessing, and the guess tends to flatter whichever choice is more comfortable.