Rick Riordan said this quote
“ He remembered how nice the kids at Camp Half-Blood had been to him after the war with Kronos. Great job, Nico! Thanks for bringing the armies of the Underworld to save us! Everybody smiled. They all invited him to sit at their table. After about a week, his welcome wore thin. Campers would jump when he walked up behind them. He would emerge from the shadows at the campfire, startle somebody and see the discomfort in their eyes: Are you still here? Why are you here? It didn’t help that immediately after the war with Kronos, Annabeth and Percy had started dating … Nico set down his fartura. Suddenly it didn’t taste so good. ”