Herrera swapped Manchester United for the French capital last summer and said his preconceived view of Neymar as a negative influence at the club has been blown apart since arriving at the Parc des Princes.
"He is one of the big surprises I have found in my career because when the media speaks it is not always positive," Herrera told ESPN. "They are always trying to find a way to kill him.
"But I found a guy who is happy every day, that is trying to make the group strong. He organises dinners at his house so we can be together and he tries to win us as many trophies as possible.
"He is smiling every day and creating a good atmosphere in the team. He told me he was happier than ever in the club. It's like I read about a different player than the one that I found.
"I understand that all the people want to talk about him, maybe because of his hair or the way he dresses."
As well as Neymar, Herrera also has Kylian Mbappe as a teammate at PSG. The Spaniard said he believes the pair are "two of the top five players in the world" and Mbappe, in particular, can make training look like men against boys.
"Sometimes in training, it is like he is training with kids," Herrera said. "The way he runs, the way he moves, he leaves you behind him.
"It looks like we are kids, 12 years old, and he is Usain Bolt. And when he is in front of the goalkeeper he has the capacity to stop and be cold and to score a lot of goals. That's not easy.
"He has the balance between the speed, the strength and the calmness to score goals. In 2025, he could be the Ballon d'Or winner."
Herrera has been restricted to 18 appearances this season because of injury but the 30-year-old said he is hopeful of helping PSG lift the Champions League trophy if the competition returns in August.
He said he was not planning to leave United when he departed on a free transfer but is happy in Paris.
"It's a country of football, maybe not as much England or Spain but I still feel the passion," Herrera said. "I am living in the most beautiful city in the world in my opinion and I am living a dream.
"I am playing for one of the best teams in the world and living in the most beautiful city I have ever been to."