Why are there gaps in my memory? Right?

Someone introduced themselves as an ex lover yet I dont remember him. Only a blurry moment which he confirmed. But other than that there are no other problems. Because when I think about it too much my head hurts and I think its normal for someone to not remember much about their childhood right? Though there are memories in my head that I dont think is mine, is that possible? Is that normal. Sometimes I just think that those were memories from dreams. So nothing to worry about right? Lately Ive been having too many migraines sometimes I think are caused by overstraining my eyes, though most of the times because of my elevated emotions that I keep under control. Its so annoying and painful. But theres nothing to worry about it right?