I first became aware of the best-in-the-world ranking of Finnish schools in the excellent book, “Under Pressure: Rescuing Childhood from the Culture of Hyper Parenting” by Carl Honore. (This is probably one of the best books I've read so far this year and would highly recommend it, whether you are a parent or not. A lot of it applies to expectations of today's children in public settings like libraries for instance.)
This article explains some of the reasons why Finland is so far ahead of the curve including extended, high quality pre-school, delineated high school and free higher education.
From the section related to their first example:
In all three Scandinavian countries students begin formal schooling
only at age seven, two years after most American children begin school.
However, prior to entering school, all children have participated in a
high-quality government funded preschool program. As opposed to a focus
on getting a jump academically, these early-childhood programs focus on
self-reflection and social behavior. It is interesting to note that one
of the most notable attributes of Finnish children is their level of
personal responsibility. The early focus on self-reflection is seen as
a key component for developing that level of responsibility towards
learning.