After 30 years working in various scientific jobs, as a plant ecologist, science editor, science teacher, and science writer for Te Ara, the online encyclopedia of New Zealand, she thought she had a pretty good general knowledge of New Zealand's natural history and geology.
"So I was surprised to learn in 2004 that geologists considered Wanganui's coastal cliffs to be of international significance.
"Because although I was aware of the cliffs, I'd never given them much thought. They were just part of my childhood backyard."
The cliffs had been well studied for a 100 years or so by a gaggle of geologists and fossil fossickers. Sir Charles Fleming had provided the definitive study in 1953.
"Done and dusted as far as I was concerned," she said.
However ten years ago she joined some geologists on their field trip to Wanganui's coastal cliffs and found out they had been studying the area intensively over the previous decade and had established that it was one of the best sites in the world for displaying a record of repeated sea-level rises and falls during the last 2.5 million years, she said.
The geologists pointed out features at outcrops along the cliffs, and when she checked the field notes she had been given to consolidate what she had heard she was immediately confused.
"I was bamboozled: the notes were replete with a complex vocabulary and referred to scientific techniques and ideas that were new to me."
She decided to get to grips with the jargon and concepts associated with sedimentary science and the quaternary history (last 2.5 million years earth history) of the cliffs "but the Wanganui coast is much more than a grand geological record."
In telling this story of modern geologists detecting detail in sediments she has added some context and described the coastal environment, its creatures and plants.
"This is the type of information I would have loved to have had when I was growing up in Castlecliff."
She recalls vividly the ironsands of Whanganui-South Taranaki.
"I've known about ironsands since I was a toddler and got burnt feet when walking barefoot on Castlecliff Beach.
"I was a bit too young to appreciate the physics at work ... the ironsands are dark so absorb heat quickly and transmit it rapidly to tender soles of the feet."
In her book she has explained that the black sands originate from volcanic rocks in Taranaki and the central North Island and the rivers carry sediment eroded from the volcanoes out to the coast.
"This is where waves and currents transport the sediments far out to sea or sweep them down the coast. The heavy iron-rich minerals in the sediments are deposited close to shore."
Over the last 18,000 years the location of the shoreline has changed and there are vast deposits of iron-rich sands now located many kilometres out on the South Taranaki Bight at water depths up to 30m, she said.
A proposal to mine billions of tonnes of these offshore ironsands has recently been rejected by the Environment Protection Authority (EPA) based on uncertainty about environmental effects and lack of clarity about economic benefits.
Whether you were for or against the mining, one benefit of the proposal was that a flurry of scientists started investigating what was living in these underwater sand dunes, she said.
In her book she says their verdict was "not much, with the exception of a worm, known as Euchone A."
"This worm is not like your common garden worm, but is a bristle-worm that lives in tubes of cemented sand-grains within the mud layer above the ironsands.
"And that's about the extent of our knowledge of this wee worm, for where it lives is such a stormy and hostile environment that scientists kept losing their monitoring equipment when they tried to study whether this worm could recolonise mined sites."
Dr Wassilief, who has retired to Gisborne, said it was easy to take familiar surroundings for granted when she was young, and dream of exotic climes or sophisticated cities where adventures abounded.
"I never thought I'd write a book about life in the coastal cliffs from Wanganui to Hawera ... I have and am very pleased I did. It's been very satisfying."