If I remember correctly, it did take a few years. There was a lot I wanted to make sure of. That it cause heavy interference with the Pokemon who already lived there, for one. I would say that added an extra year on top of everything...

Then there was the matter of ensuring that anything that would be used to make the island would also not disrupt it. Then came the process itself, making the grounds stable enough to hold everything we needed...

[Hmm.]

It's certainly not a process for the impulsive, that is certain.