At some point, it stops happening on its own.
Our vocabulary doesn’t expand from reading easy books and having familiar conversations using the words we already know.
It happens when we read hard books, perhaps working a passage over many times. And it happens when we engage with sophisticated people and pay attention to what they say.
Our climbing vocabulary works the same way.
We get to a point where easy climbs and familiar climbing partners don’t make us better.
If we want to expand we should seek hard climbs with movements we don’t understand right away–not until we’ve taken time to work through them.
And we should seek climbing partners who are better than us and pay close attention to how they move.