The 61-year-old even conceded that he could "count eight teams" who had a better shot at glory than the Oranje
The Netherlands currently lead Group D in Europe qualification with 18 points and can book their ticket to Brazil with a win against Estonia on June 9.
But despite dreaming of hoisting the World Cup next year, Van Gaal said his thoughts remained 'real' about their chances of success.
"(Winning) would be a surprise, but I don't think so," he told ANP. "I can count eight teams who have a better chance of becoming world champions than Netherlands.
"I'm always real. I dream of becoming world champions. That's what I love for. That's why I'm the coach."