# Why not memorize everything Human memory is both fragile and capricious. Relying on it to retain all our knowledge is actually risky. Short-term memory (STM) is obviously limited in size and retention is very limited in time. Long-term memory (LTM) is seemingly infinite but subject to [memory decay](https://en.wikipedia.org/wiki/Decay_theory) and [interference](https://en.wikipedia.org/wiki/Interference_theory). For instance, when learning new things and storing those in our long-term memory, it happens that the new knowledge interferes with the retrieval of known information. The truth is that we all keep forgetting things and losing access to information we know we have in our heads. We can try forcing everything into our long-term memory, but it may not be the best solution. ## References - Memory decay theory: https://en.wikipedia.org/wiki/Decay_theory - Interference theory: https://en.wikipedia.org/wiki/Interference_theory