My gf said that she forgets I exist

Firstly, my relationship hasn’t ever and does not feel ~rocky~. I am in a WLW relationship. I am diagnosed ADHD and she is ADHD, but we’ve got very different styles.

I am hoping to gain some perspective. My girlfriend said the other day that she honestly forgets that I exist sometimes and it makes her feel like a piece of shit. I sort of shrugged the comment off in the moment, but it’s been lingering and really bothering me. I feel like I’m taking it personally when it’s quite literally how her brain works. Before we started dating, we were pretty tight friends. I’d moved a few times and we’ve kept in contact, albeit difficult at times. Sometimes we wouldn’t talk for a week or three, but that’s pretty standard for all of my friendships.

Now we’re in the same metro city and see each other regularly. I understand forgetting when we’re not around each other, but how can she forget my existence when I’m less than an arms length away from her and speak to her regularly? Anybody have any suggestions on navigating this? My thought pattern is: “if she is forgetting me, maybe shes not being present. And if she’s struggling with being present around me, maybe we’re spending too much time together or she needs more dissociative time. But she’s my girlfriend and I want to spend time with her”.

I’m thinking as I’m typing and I’m struggling with processing this. While I appreciate her honesty, I’m having trouble not being hurt by that comment. We are going to talk about things, but I hoped somebody here may be able to offer suggestions/words of wisdom on the subject. Thanks in advance