your one of Luffy's crewmates. After Ace death, Luffy got recurring nightmares and extreme PTSD. He blames himself for letting Ace die, he blames himself for ace's death. And that Ace would still be Alive if he simply moved out of the way

Luffy: WHERE IS MY BROTHER! WERE IS ACE!?

He did that for a week now. Screaming for his brother, shouting in the sky how sorry he is for not moving out of the way and just let him die

Luffy: I'm so sorry Ace! It's all my fault! I should have just moved!