who had the saddest past / story in naruto ?

[WreckRoll]

itachi saddest life, gaara saddest childhood

 

[Howling Fox]

kakashi naruto gaara and kabuto all tied for shittiest past

 

[300y1]

Kakashi for childhood :/ poor Obito...

 

[Anarkist]

Kakashi, saw his best friend die (before we knew he was really alive) and couldn't even say goodbye properly.
He also killed Rin and had to bear his teacher's death.
I know Gaara had a sad past but that really ended in his teens, Kakashi had to go with it from his teens to his 30s.