Often the learning processes of adults do not fail due to lack of intelligence or lack of effort. Rather, it is the suitable thinking tools helping to understand complex information and solve problems that are missing.The publication describes the approach, process and the results of the extensive project study "KLASSIK (Kognitive Leistungsfähigkeit im Alter zur Sicherung und Steigerung der Informationsverarbeitungskompetenz, cognitive performance in old age to ensure and increase information processing competences)". 350 seniors of ages between 50 and 90 years took part in that study. The project, which is funded by the BMBF (Federal Ministry of Education and Research), could prove that the targeted use of easily learnable metacognitive techniques is perfectly suited to increase cognitive abilities and to overcome barriers to learning. Slower learners, in particular, benefit from such an approach.