In the context of research on life-long learning, the present study focuses on the question if active memory trainers have a realistic estimation of the cognitive capacities of their trainees. A second question targets the influence of pre-post-tests as an integral element of memory trainings. The study is based upon a survey among the members of a German-wide operating memory trainer organisation, the "Bundesverband Gedächtnistraining e.V." 183 persons participated in the survey. Results show that the trainers have a relatively accurate and differentiated view about the general cognitive capacity of their trainees. Although pre-post-tests are rarely used, data reveal that they enhance the correlation between the estimated possible gain and the estimated improvement after the training. In general, the results of the present study support that pre-post-tests should be applied as an integral element of cognitive trainings as they make them more effective by providing the trainers with more accurate information regarding their trainees.