NimtheWriter
From what I remember,the reason why Shirou doesn’t remember a-lot about his parents is because of the cursed nature of the fire and age.That cursed fire burned everything,even Shirou’s original origin and personality was burned away.Shirou was literally a blank,broken canvas at the end of it until he meet Kiritsugu.Now he did have a broken memory of his mother,but he didn’t want to think about it too much.So basically Shirous’ memories was either forgotten or just straight up erased by the fire.Shirou,as a person,died in that fire and had come up with a personality from Kirisugu and his behavior and ideals.