I have printed those words of wisdom below on an OHT, which I show to every class that I teach:
Whatever the education system may offer,
the lessons in school do not create value
until they enter the human brain and get processed.
Since the human brain is biologically defined, it is the most
important bottleneck in the education system. A student can
be surrounded with the best teachers and provided with the
best textbooks, BUT unless he has the capacity, the
concentration and the will to learn, all of that is useless.