Just to follow up: it's compounding. Like compound interest, it gets big surprisingly fast. Another example is that story of placing one grain of rice on the f

Just to follow up: it's compounding. Like compound interest, it gets big surprisingly fast. Another example is that story of placing one grain of rice on the first square of a chess board, and doubling it for each square, so 2 grains on the second, 4 on the third, 8 on the fourth and so on. You end up with 2 64 (2 to the power of 16), or about 16 million million million grains of rice.