Quote from : The Blood of Olympus Book

The main thing about ghosts – most of them have lost their voices. In Asphodel, millions of them wander around aimlessly, trying to remember who they were. You know why they end up like that? Because in life they never took a stand one way or another. They never spoke out, so they were never heard. Your voice is your identity. If you don’t use it,’ Nico said with a shrug, ‘you’re halfway to Asphodel already.’ … He hated when his own advice applied to himself.