I think of all the times I studied as a student. So many times I think they left the memory bank once I used them on say a test. I think that is common though.

This depends on where those memories are stored, in your long term or short term memory. Those who are studying a day before the test, just to pass the test, will forget everything, unfortunately.

What is challenging is recalling your very first memory.

Oh God! I didn't want to mention this in my post because I tried and can't remember what was my first memory 😬

And yes, I got to see a lot of photos and learnt a thing or two from my dad, but nothing usable these days as photographing has changed completely 😄