Asked my bf did he miss me…he replied

I asked my boyfriend if he missed me and he said sometimes (which is normal) 😂😂 we spend a lot of time together. He explains further and states that he gets super sad when I leave then 20 minutes later sometimes it still feels I’m there with him so he doesn’t and that he miss me alot when we’re both busy.

I’m pretty sure I’m over analyzing at this current moment but what does he mean by it still feels like I’m there.

He’s super sweet. I guess I’m just in reflection and I don’t know what that part means.