Forgetting People

So I've always been a forgetful person and I forget objects or people I don't know well quite frequently, but lately I've noticed that I've been forgetting my boyfriend on some level. He lives about an hour away from me so I only get to see him around once a week which has always been fine in the past, but these past few weeks I've noticed that when he comes to visit after a week of not seeing him, I feel like in that time I've forgotten him much like the way you forget an old friend you haven't spoken to in years or a passed away loved one. You know how you still remember the person and you know who they are and about they're life but for some reason the essence of that person has seemed to slip from your mind. I know who my boyfriend is but it's felt lately like every time I see him after a week that I find myself having to take time to get used to him and remember him and let my brain process him and accept that this is the person that I've been dating for a year and a half. I don't really know how to describe it. I can't fully grasp what's helping in my mind when all this is happening, and I was just wondering if anyone else has experienced this. When I asked my boyfriend he said it made sense and it was valid but that he'd never experienced it before. I guess I just want to hear from someone who has experienced this to make me feel not so different and to kind of explain they're experiences with it. If it helps in understanding the situation I have PTSD, depression, and anxiety. Thanks!