Nothing gets Welsh blood boiling faster than a barb hurled this way from across Offa’s Dyke. Turbocharged by historic oppression and the adrenaline of umbrage, there is no taunt too trivial that it cannot end up being amplified into headline news. Habitual perpetrators of anti-Welsh put-downs – Rod Liddle, Jeremy Clarkson et al – are monitored with hawk-like ferocity.

Yet perhaps there is an equally longstanding English attitude towards Wales that causes just as much damage: an over-romanticism that frames their small western neighbour as balm and refuge from the vicissitudes of modern life. As an English Midlander who fell in love with Wales as a youngster, and moved here 20 years ago, I know this affliction all too well. In researching my book On the Red Hill, I found plenty of fellow sufferers.

Wales as mythic retreat is an idea that never dies, but shape-shifts down the centuries. From young bucks compelled by the Napoleonic wars to pursue their Grand Tour in Snowdonia rather than Switzerland, to today’s purveyors of glamping and gong baths, the vision of Wales sold beyond its border is eternally soft-focus. And it always works a treat. The land of crags, castles and bards stirs a particular kind of English sensibility, one perpetually prone to wistful nostalgia for simpler times, simpler places.

Inevitably, this escapist appeal is sharpened at times of crisis or bewildering change. Continental slaughter and rapid industrialisation at the end of the 18th century gave birth to the first wave of “picturesque” tourism, with Wales the destination of choice.

In they poured, clutching volumes by William Gilpin or Samuel Taylor Coleridge, who had found “the wild-wood scenery” of Wales “most sublimely terrible”, surpassing “everything I could have conceived”. For George Borrow, high priest of English Celtic romanticism, Wales was “a truly fairy place”. Later, as the Victorian era reached its sooty zenith, Welsh beauty spots were repackaged as its sugary antidotes: Fairy Glen, Swallow Falls, Happy Valley, Little Switzerland and the like.

In the 1930s, as storm clouds gathered once again, so did enthusiasm for Wales as Arthurian kingdom and crucible of the old ways. Hippies in the 1960s and the oil crisis of the 1970s repainted the image in shades of vivid green, while in this past decade of anxiety about technology and isolation, up steps Wales as digital detox, nature’s own gym and close-knit community of smiling cwtches.

Cheap housing too, of course – the rather grubbier lodestone of our age. Relocation to the rural idyll is no longer a transitory urge but an ambition for a brand new life. But the dream sours all too swiftly, for nothing real can survive in its seductive half-light. All too often, from the disappointment comes fury.

This, too, is a long tradition. Poet Walter Savage Landor, wowed by the estates built in picturesque style across Wales, breezed into the Black Mountains in 1807, determined to create his own. As nature writer William Condry put it, Landor “spent £50,000, planted many trees, quarrelled with everyone in sight then departed.”

Many of his problems were self-inflicted, such as planting thousands of trees that locals rightly told him would never grow there. On his departure from Llanthony, Landor fired off an angry letter to the Bishop of St David’s: “If drunkenness, idleness, mischief and revenge are the principle characteristics of the savage state, what nation… in the world is so singularly tattooed with them as the Welsh?”

Over the past half century, the trickle of English idealists escaping to Wales has become a torrent. Godfather of them all was John Seymour, author of bestsellers The Fat of the Land and The Complete Book of Self-Sufficiency, who bought a farm in Pembrokeshire in 1964: “I was back in a peasant society where people still brewed beer and killed pigs and we were no longer freaks,” he wrote. In the late 1980s, he too flounced out of Wales, declaring that it was by then “insufficiently authentic”, whatever that meant, and resettling in Ireland. Other green gurus have since come and gone, often hurling disappointed brickbats as they depart.

Facebook Twitter Pinterest Photographer George Walton, above right, and his boyfriend Reg Mickisch, moved to rural Montgomeryshire in 1972 to open a guest house. Photograph: Mike Parker

In On the Red Hill, I tell of this process of deflation happening in the diaries of George Walton, a photographer who moved to rural Montgomeryshire in 1972 with his boyfriend Reg Mickisch, to open a guesthouse. For Walton, inspiration came from Shelley, Wordsworth and Coleridge, rather than Seymour, and in his first couple of years here, he began writing a poetry collection entitled The Secret Land: Poems and Songs of Powys, Mid Wales. Not only was the land “secret”, it was “lost… long-forgotten… lonely… slumbering… dead”: words that habitually spring forth when English eyes first sweep across rural Welsh landscapes.

In truth, these fields are anything but forgotten; they are named, tilled, fenced, improved and fiercely fought over every time a tenancy agreement comes up for grabs. Reality bit George hard, especially on the eruption of a vicious neighbour dispute that killed any last traces of his Secret Land. Wales, he decided, was not lost or slumbering; it was clocking his every move and plotting. From then, the tone of his diaries changes markedly. “Welsh” often becomes a compound term of derision: “that Welsh communist”, “Mrs Welsh Bigmouth” and so on. It is never used as a compliment.

The challenge is clear to those of us who have crossed the border and made Wales our home. It is to embrace the fullness of life here, in all its contradictory muck and majesty. Most of all, it is to learn to see Wales by its own definition, on its own terms, and not as some otherworldly counterpoint to benighted England. The reality is far more interesting, and yes, difficult and complicated, than the dream.

Mike Parker’s book On The Red Hill (William Heinemann, £16.99) is out on 6 June.