What is it that you describe as “emotionally numb”?

Id say when I’m emotionally numb I Iiterally have the inability to feel for others and I’m just kind of sitting there with all my thoughts and nothing makes me happy, sad, angry, anxious, or just upset in general. But that only happens every so often to me. I’m not quite sure how to explain it 100% bc it’s almost like I turn into a completely different person and forget who I am so as a result I end up emotionally numb and just can’t really emotionally connect with anything or anyone. I’m not sure if that’s the same for others as well but that’s a little run down of how it goes for me lol