What is the overlap between aphantasia and absence of memories? The example you gave was that you couldn't remember going to see Les Mis a year before, so that's not stored as a fact somewhere?
There was a (possible hoax) story a while back about a guy who could only remember the previous 15 or so hours of his life. He kept journals and had to jog his memory daily. One interesting proposal was that he was in a unique position to re-watch his favourite movies and compare his previous reviews to see, unbiased, if there was any change in opinion. Aside from the awfulness of the condition, that particular aspect sounded quite cool - you could experience things for the "first time" multiple times.
Does the same thing occur with aphantasia? If you see a movie that you love, presumably you can't remember any scenes from it later (though you I assume you would remember the plot)?