Jay continues to always see Jun in the most positive life. He wants to find the truth, but he still only wants to find the truth that matches with his expectations and makes
him feel better. Jay has advocated for the importance of sharing hard truths, but when Mia tries to share a hard truth about Jun with Jay, Jay dismisses it. While it’s not clear that Mia is entirely right in her assessment of Jun, either—for instance, it wasn’t Jun who stopped writing to Jay, but Jay who stopped writing to Jun—it seems likely that the truth lies somewhere in the middle of Mia and Jay’s separate assessments of Jun. Jay’s sadness at finding that the child isn’t Jun’s is grief that Jun is truly gone—that he doesn’t “live on” through a child. And there appears to be still more of a mystery to Jun’s life, as Reyna apparently knows nothing about the website that Jun seems to have run.