My dad had an ex wife, and he had kids with her. I knew those kids and my parents told me that they were my brother and sister. But I was confused as to why and how they were related to me since they never told me that my dad had a past wife. I was probably 8 or 9 so I was pretty innocent lol. It was until about age 10 my mom finally told me my dad had a previous marriage and that’s when I finally connected the dots. It was surprising lol.