People have a very short memory; they don't remember what happened yesterday. However, they will permanently remember the emotion that the disinformation evoked in them.
I also know a very juicy, authentic example of a real person. A certain religious conservative, around 2013 to 2015, fell for a hoax intensely spread by pro-Kremlin websites that Minister Lajčák secretly wanted to sign some fictitious secret document that would oblige Slovakia to turn children into transsexuals in schools (it wasn't the Istanbul Convention, I think it was some other nonsense). The Christian even collected signatures for a petition against gender ideology and against the ministry's secret dark plans.
Today is 2019. The Christian in question no longer believes in hoaxes or alternative media, but when it comes to Lajčák, he will tell you, "I don't know why, but I find Lajčák somehow unlikeable, I sense something bad about him, I think he's a dubious person." If you ask this person for arguments, he has none; he just has a bad feeling about Lajčák, and that's all, and he aggressively and angrily stands by his opinion.
However, the Christian in question quickly forgot how he had fallen for the hoax in the past about Lajčák's secret, dark conspiracy with gender ideology and that he had collected signatures for a petition at a Christian pilgrimage based on this hoax.
Even if it turns out that a message is a hoax, people quickly forget what nonsense they fell for, but the emotions from this hoax remain in them.