Nah, he just realized dobin was his therapist and we only saw Tae Oh having a recollection, a memory he remembered during his childhood. Some kids don't remember some things from their past and considering the early chaps, he went away to another country so thats also a factor. Dobin having fuzzy hair and Tae Oh rubbing it was what triggered the memory that was 'forgotten' and this last chapter would be pretty much the main trigger at least if ever to remember those memories. Idk if I make sense but yeah, I'm also not saying this in like a rude tone or something, pls believe me.
Oh alright, thanks! And I didn’t find your tone rude at all, so no worries (づ￣ ³￣)づ
I thought Tae-Oh had already recognized who Dobin is after he got drunk at the hotel and said he was his therapist and he saw his fuzzy hair?!