Napoli knew they had to beat Juve, at their place, to have any realistic chance of having a real go at the title. They haven't won the league in nearly 30 years and have seen Juve sweep aside Serie A for quite a while now. Think the celebrations are fantastic, and the fans probably realize they could help spur the team on now to win their remaining games. Nothing wrong with having belief in backing the team to the hilt. Think this tweet from this morning is quite accurate:
Huw Davies
@thehuwdavies
I love those Napoli celebrations. I’m also wincing at the thought of how British football Twitter would react to, say, Liverpool fans going all out over a win that keeps them in second. Joy is not welcome here.