The Dutch begin their campaign in Salvador on Friday with a rematch of the 2010 final against reigning champion Spain as it bids to qualify from a formidable-looking Group B.
Australia and the highly-rated Chile await in the other two group matches, but nothing has dented Van Gaal's confidence in his team's ability to go the distance in Brazil.
"I also feel the tension in my stomach," he added. "If you play such a big tournament, of course not everything just depends on your technical and your tactical skills. We saw that [in Brazil's win over Croatia], for instance - you can't control everything."
"You have to enjoy yourself," he told reporters. "You can’t be serious all the time. You have to release the tension. Cope with the pressure. We have five weeks here. Make no mistake: we will be here for five weeks."
However, the incoming Manchester United manager admitted the prospect of refereeing decisions making the final difference between success and failure at the World Cup makes him nervous.
Spain is widely tipped to top Group B as they bid to win an unprecedented fourth consecutive major international tournament, and Van Gaal was full of praise for their enduring success.
"Spanish football might be the best in the world, with the physical and technical sides all linked up," he insisted. "I like the dedication of the Spanish players. They are ranked No.1. We are ranked No.15. We have to play a compact game against them.”
Van Gaal was also quick to play down speculation that the protracted saga which led to his announcement as the new United boss might have affected his ability to prepare for the World Cup with his country.
"Distraction? Well, it may be a distraction," he admitted. "But perhaps Manchester United was a good distraction."