When Finland's school system was ranked the best in the PISA test, educators from all over the world began to study the experience of Finnish colleagues, trying to understand what their secret was. The American teacher Timothy Walker, who worked for two years as a teacher in a Helsinki school, argues that at the heart of all the achievements of Finnish schoolchildren is a simple principle: the educational process should bring joy. A short school day, a minimum of homework and testing are only external components of successful training.