How has the concept of knowledge changed? Is the language still adequate to grasp the complexity and specificity of our times, while at the same time being more inclusive, innovative, and open to an interdisciplinarity? The paper discusses the changes that have taken place in the last decade in the way we think, conceptualise, represent and access knowledge, focusing on the implications for our behaviour and beliefs. Darkness (ignorance) and light (knowledge) is a familiar feature of our language, whose significance is often overlooked. Darkness and light have become almost frozen metaphors. Darkness is largely based on images of absence, ignorance, or that which cannot be understood (black hole memory). Light, on the other hand, stands for enlightenment, insight, clarity, hope. This paper want to show that the concept of knowledge, although based on the idea of an ordered system of data and information, is actually related to an idea that should take into account the heuristics of darkness in addition to the light of knowledge.The organisation of knowledge is in fact much less structured than one might expect. This implies a paradigm shift that requires moving away from the dichotomous interplay between "dark and light" as a metaphorical model. Instead of the fixed classification or structured model, there are many other ways of organising and representing knowledge (even in the texts) that help to resolve the tension between "inventory" (storage and classification of knowledge) and "inventio", discovery, the continuous renovation that produces new knowledge, avoiding monolithic and dogmatic positions between "memory and oblivion".