God knows how UN experts counted and how they found out the little Matej Gaspar was the five-billionth Earthman. Anyway, the Five Billion Day was celebrated. Later, it was decided to celebrate it each year and to give it a name, a rather awkward one: World Population Day. Let’s not make indiscreet assumptions about how it is suggested to celebrate it. Instead, let’s think about another problem: if it took thousands of years to reach the first billion of its population, which was done by the beginning of the 19^th century, the fifth billion appeared frighteningly fast, just in 10 years, and the sixth one, still faster, by 1999. Well, that is something to think about, especially for developed countries whose population nearly stopped growing.