I was thinking the other night about when little Anakin is talking about seeing Qui-Gons "laser sword" and says that no one can kill a Jedi. Qui-Gon then gets an almost sad face and says "I only wish that were true". Could it be possible that he foresaw himself getting killed by Maul? As far as I know the Jedi didn't die unless by accident, natural causes, or the occasional peace keeping mission death. The Jedi had no one to fear in these times because it was before the Sith revealed themselves so what would cause Qui-Gon to make such a statement except for him seeing the future?