This linguistic confusion is why Americans call the Pennsylvania Dutch Dutch even though they're Germans. To review: this country is the Netherlands, its people are Dutch, they speak Dutch. There is no country called Holland, but there are provinces of North and South Holland.
In clean, uncrowded conditions in tanks or ponds, goldfish grow fast. They can grow to a few inches (1 to 4 inches) within the first year. It really depends on their genetics and living situation. It may take a year or two before they change color from brown to gold or whatever color their parents were.
The average life span of a pet goldfish is five to 10 years. In the wild, they can live as long as 25 years. In fact, the oldest goldfish ever recorded was 43 years old. But prolonging the life of your fish depends on proper care and tank environment. Goldfish require a lot of upkeep.