There are several meanings of "anamnesis". It has a meaning in the Christian faith, which I will ignore here, but there are two more- one as a philosophical meaning and the last one as the more well-known medical one. The introducing image on the side, is an example of an anamnesis experience in the philosophical terms , where Tom Hanks as Joe Banks has his "insight" in the wonderful movie, Joe and the Volcano.
Some more background on the philosophical meaning
According to Plato, the most important forms of knowledge come not from instruction, but by a re-awakening of already existing dormant or latent knowledge. This is called anamnesis and it is the idea that humans possess knowledge from past incarnations and that learning consists of re-discovering that knowledge within us.
Anamnesis comes in the form of "deja-vu" or "aha!" experiences -- insights, moments of unusual clarity, peak experiences, etc. It involves only certain forms of knowledge: moral- (e.g., what is goodness?), existential- (e.g., what is the authentic 'me'?),spiritual - and mathematical.