Reminiscence is the act of recollecting past experiences or events; when a person shares their personal stories with others or allows other people to live vicariously through stories of family, friends, and acquaintances while gaining an authentic meaningful relationship with a person. Grandparents are often ones who reminiscence their stories to their grandchildren, sharing their individual experience of what the past was like.

The study of reminiscence has a long history, which is shortly described in Eysenck and Frith (1977, chapter 1):

Reminiscence is a technical term, coined by Ballard in 1913, denoting improvement in the performance of a partially learned act that occurs while the subject is resting, that is, not performing the act in question. (Eysenck and Frith, 1977, page 3).

The reality of the phenomenon

Phenomenon

A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...

 was first experimentally demonstrated by Oehrn (1895). In experiment

Experiment

An experiment is a methodical procedure carried out with the goal of verifying, falsifying, or establishing the validity of a hypothesis. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results...

s on reminiscence the same task is always administered twice or more. One is mainly interested in the effect of the rest periods between the tasks. Learning might not be apparent within a task but it may be across tasks.