Why is Germany livelier than other european countries ?

Man, you can't make such a general assumption. Even you saying that "all the European countries are the same" is stupid. There are not just differences between the countries, but there are differences between the regions inside a country. In every European country, you can find calm places where people live calm lives, and you can find big cities where a lot is going on and people don't have time to greet every person they see on the street.