Ok, these episodes are 176 instances over 7 years. You've listed 10 "twisted reality" episodes. Roughly 10 of their days out of 2557... It's not all THAT common.
Plus, in Remember Me, Crusher was INSIDE her own reality, no one believed her because all of those people weren't real. Besides, they were all humoring her and trying to find her friend at the beginning, and were trying to figure out what was going on. Even they were all creations inside of her own reality bubble.
And then Riker, in Future Imperfect, was inside a hologram created by the boy. Of course the boy would make the characters not believe anything was wrong, in an attempt to convince Riker that nothing was wrong.
Picard in The Battle? That was towards the beginning of the series, during season 1, so obviously they are all new with each other, besides, it started out as Picard just having unexplainable headaches, it's not like he suddenly started acting like someone else or had some odd thing happening to him that no one believed was actually happening to him.
And if Realm of Fear is the one with the whole people in the transporter beam, Barclay was overly paranoid and scared of everything. Boy-who-cried-wolf syndrome. It's understandable that they wouldn't believe anything was happening to him.