The importance of 10 %

You often read about the Chinese economy growing 10 % per year (less often about the Estonian economy, which also grows at 10 % per year). But what does it mean, really?
If I have 1 million yen, and they grow 10 % every year, that means I have 110000 yen after one year, and 1210000 yen year 3, and 1331000 yen year 3, and 14161000 yen year 4, and 1610510 yen year 5, and 17715610 yen year 6, and 1948717 year 7, and 2143518 yen year 8. So in eight years, there is a doubling of the capital, if the growth is a steady 10 %.
This is counterintuitive. People have a hard time thinking in terms of rent and probabilities. As a spieces, we are not particularly calculating, we are risk-takers. The fable of the Indian king who was asked by a sage to reward him by putting one grain of rice on square one of the chessboard, two on square two, and so on, is also counterintuitive. Yet it is sort of the same: If growth remains at a steady rate, things get big fast.
You see this in China today, and if you had the benefit of going there 20 years ago (as I did), it becomes even more clear. Yet if you start from 1, going to 2 will take you 8 years. However, going to 3 takes you only four years, and to 4 only three years. So by now, they have gone from 1 (20 years ago) to 7. And growth in absolute numbers is becoming faster, even though the pace may deccelerate.
However, once you are a millionaire, being a two-millionaire probably does not make you twice as happy. The marginal utility of money decreases. It does not start to increase again until it reaches a level where you can spend it and get something. Just to give an example: A million yen will buy my wife and me a week in Tahiti. But it will not buy a house, for that we need at least 50 million. So, we will be happy as clams once we have made (or rather, spent) our first million, but then its a long hard slog until the house.
It is the same for China, or Estonia. Euphoria all around until everyone has all the basics. And then, a long hard slog until you reach the point where people could stop working if they wanted to. It happened in Japan and Sweden, and Germany as well. Why not in China and Estonia?
But that will take some time. From 1 to 7 is 20 years. From 7 to 50 another 20, or 30 (since the "50" is figurative here). In other words, China may be as rich as Japan was in the beginning of the 60's (the similarities do not end with organizing olympics), but to be as rich as Japan is today, that will be another 40 years. At least.