It’s heartbreaking that, even though we’ll never get to know who Kaufmo really was, we get to see how much everyone in the circus cared about him

Kaufmo could’ve been anyone, and in that sense, he could have also been everyone. Any characterization he has is up to the audience.

Ultimately, it doesn’t matter who he was, what matters is the lesson we and Pomni learn from how everyone remembered him: no matter how alone you think you are, there’s always someone who cares about you. Whether it was Pomni’s fear of abstracting and being forgotten or Gummigoo’s crisis over realizing he wasn’t real, they both had people who cared about them. Even now that Gummigoo and Kaufmo are gone, they still live on in the memories of the people they mattered to.

Whether Gummigoo in episode 4 remembered Pomni or not, what matters is that all that she did for him wasn’t in vain. Even if he doesn’t remember her, she remembers him, and that’s more than enough.

No matter how insignificant you think you are, people care about you more than you can imagine.