I catch myself including details from books in my own memories

I just recalled a time where I was working on a school project with a girl. She lived with her grandmother. Her grandmother made us some chicken and egg salad sandwiches. They were too filled with mayonaise and on the softest, weakest bread. I was remembering her living room and included a painting of a naked girl swinging very high into the air on a swing. Then I remembered her living room did not have that painting, I just remembered that detail from a novel. I put the novel detail in my memory.

I did this another time, walking around downtown looking for a mural where all the depicted people had their hands in their pockets because the artist who painted it depicted hands poorly. That too was a detail form a novel. I've never seen this mural.

I don't trust my memory much because of this, why do I embellish recollections with other people's ideas? Surely the details of my own life are interesting enough? I can't remember the books these memories come from, either. It's just "a book."