For whatever reason, humans are perceptually attuned to quick movement, rapid change.
Thus we notice movement in a landscape long before we notice the landscape itself. Or indeed changes in the landscape. Last week I watched with a student a talk given by Chrystia Freeland on the surge in worldwide income inequality. Why, she asked, were we not more enraged by the dangerous phenomenon?
To illustrate one possible explanation, she used the metaphor of the boiling frog. It used to be believed that if you placed a frog in a pan of boiling water it would simply hop out, but that if you placed it in a pan of cold water which you then brought slowly to the boil, the frog would not notice the incremental change in temperature, and would stay put until it was cooked.
This is in fact not true – frogs leap from any uncomfortably hot water, as you would expect. But if it is not true of the frog, then it true of us, as the aristocrats of the Ancien Régime noticed to their cost after 1789 – and as any student of a language will notice when to their surprise, after the endless unchanging plateau of intermediacy, they find themselves suddenly nailing a third conditional in free speech, unprompted and uncorrected; or reading and discussing an article from the New Scientist without batting an eye. Learning a language may be a slow business, but it is also a boiling frog.
Here, in case you’re interested, is the talk by Chrystia Freeland.