Frenchman Vergne told Spain's El Confidencial newspaper that he is now over the disappointment of missing out on the departing Webber's seat at the premier Red Bull Racing team to his 2013 teammate Daniel Ricciardo.
Vergne, 23, was asked if he thinks Australian veteran Webber, who is heading to Le Mans with Porsche, quit F1 because he got "tired" of spraying champagne on F1 podiums.
"I don't think he got tired of that," Vergne answered. "He got tired of his teammate winning all the time. And another year of the same made no sense to him.
"He would not even be happy if his team continued to win everything -- you have the same car but you're beaten every weekend by your teammate. You would get tired of that," he added, "even when you are on the podium.
"I think Mark is a very good driver and a true competitor," Vergne explained, "but things were not going as he wanted.
"If your teammate is always beating you ... the goal is to win, not finish on the podium," he added.
Vergne was also asked about F1's sweeping changes for 2014, and he admitted that the move to the new turbo V6 engine will be "the main issue" for the season.
But he added: "There are many other changes. The (blown) exhausts will be gone, the tyres will be harder. Traction will be extremely difficult and sometimes it will seem like children learning how to drive!"
And Vergne tipped Pirelli to recover from its tumultuous season, despite the fact Nico Rosberg suffered a high-speed blowout whilst testing a 2014 prototype in Bahrain recently.
"I think they will do a good job. First of all the tyres must be safe," said Vergne. "They will be more conservative."