In the first part, the paper considers the impacts of external examination on learning and school lessons. Numerous researches and analyses have shown that students from specialized high schools retain incomplete, shallow and often completely incorrect ideas about some natural and social phenomena. They do not know how to connect the knowledge that they have gained. The reason for the low applicability of knowledge and lack of retention is mainly due to the domination of shallow and reproductive studying, which is even encouraged by the external Matura. Multiple-choice questions and tasks of low taxonomic level, which can be objectively measured or graded, predominate in the external examination. The results, in the second part of the paper, indicate that the knowledge gained in high schools is narrowing throughout the years of schooling. This means that, with the approach of the final examination, exact summaries of learned material, definitions and information are demanded from students more often at the end than at the beginning of high school. Students' comprehension, linking their knowledge to other subjects and topics, critical thinking and applying the knowledge to other examples is demanded more often at the beginning of schooling (in the first year) than in the fourth year of high school (just before the Matura). Also, the democratization of the grading process decreases throughout the schooling. Students are debating with the teachers about form, methods and content of grading examinations more frequently in the first year than in the fourth year of their schooling.