There wasn't a day Haku ever wondered if he is dreaming or, if this is his own soul paradise where all soul would travel into when they died
Sure he remembered the first time he really died, a excruciating feeling of the lightning he Jutsu Kakashi-san Strike through his heart then comes the numbness as his soul left his body, Traveling into somewhere he didn't know.
He was nothing but a soul floating in the darkened plane, along with the other blobs differing in colors that he assumed as souls , all whispering to each other, but Haku remained silent as he drift off
And what it felt like eternity,he was suddenly, and forcefully pulled into the realm of the living.
He was resurrected by a jutsu known as edo tensei, Kakashi-San insisted as he fought them along with zabuza-sama
He's touched, even with a reanimated body, he's happy that zabuza-sama saw him as a family
And when he dashed infront of the Chidori once again, this time he's A happy soul
But he supposed the process of sending his soul back to the soul realm had some incident, Blamed to the clumsy reaper for example, who didn't want to be caught in trouble as he Accidentally took out a young, recently birthed soul instead of a dying mother, what's there to do?
TAKE a random soul and place it in the still warm dead baby ofcourse!
Unfortunately, that random soul is one of Haku yuki (momoichi cuz Zabuza-sama Adopted him) whom the reaper forgot to erase and remove his Chakra and memories in a hasty move, stupid, but hey it will be a historical mistake that the reaper will be proud of someday