Question: why do we have moments where we can't remember anything?

Alex Reid answered on 15 Nov 2018:

Hi Crunchy! Your brain does not want to remember everything, if you recorded all your memories as they happened it could really gunk up your memory systems. This is why over time instead our brains tend to focus on the most useful, important or relevant information.
Memory is generally considered to have three stages: memory acquisition, storage and retrieval. Not remembering something could happen at any of these stages. You might not pay enough attention to something to remember it, it might get ‘lost’ in storage, or it might not be sufficiently strong enough to be retrieved (without help). Forgetting stuff is a vast area of psychology and, as you can see, it can happen in a lot of different ways!