Oh, unrequited love.

How bittersweet, how life-changing. Most of us pick ourselves up and go on, but some – just a few, go on to let it haunt them all their days, or even, in rare cases, let it spur them on to write the great American novel. Like this guy named Scott who, 90 years ago, met a teenage girl named Genevre who lived in an idyllic summer mansion in Lake Forest. He was infatuated; she was fickle. She was rich; he was not.

He visited her at her house on Ridge Road at least twice, but most of their relationship was conducted by letter.              

The romance lasted a few years, but eventually Genevre got tired of toying with F. Scott Fitzgerald’s affections and gave him the boot. He went on to write The Great Gatsby as well as numerous other short stories in which a rich, beautiful, but self-absorbed young woman spurns a lovelorn young man. Today the graceful mansion is for sale for $5.8 million. (See listing)

Dennis Reilly, who spent his own teen years in that house, recalls, “I had read the book, but I didn’t spend a huge amount of time thinking about it. We didn’t make a big deal about it. It was just a fantastic home.”

Reilly’s mother lived there until she died last year, and now only a caretaker is around. Recently, his family put the historic, 13-room mansion at 210 S. Ridge Road up for sale, along with much of its wooded grounds. It was built in 1920, designed by noted local architect Howard Van Doren Shaw for the King family. Chicago’s wealthiest families often commissioned Shaw to design their move-up mansions.

Behind the home, a landscaped patio is designed around a large fountain with a sculpture by Shaw’s daughter Sylvia Shaw Judson. Probably her most famous work, “Bird Girl,” appeared on the cover of the book, Midnight in the Garden of Good and Evil. “I only lived there four years,” says Reilly, now a retired physicist who lives in Boston. “But I was entranced by the place. It was magnificent.” For a teenage boy, it was an ideal place to play some golf, hunt for pheasant and duck, and bring friends over to ride horses. At least, that is what he liked to do when he wasn’t taking care of the horses or mowing the large grounds.

“I was a slave,” he says, only half-joking. “In the early years, I was the outside help. We had 8.5 acres of lawn to cut, and the whole patio behind, which I rebuilt at one point. I did all the maintenance around the place. “

More recently, on a cold, early spring day, the home had a lonely aspect, set back on its estate from the road, with no parties scheduled and no fires in the fireplace and no teenagers flirting on the patio.

It’s decorated in a comfortable but grand style that befitted a home of its stature several decades ago, but it could use a romantic new owner or two to give it a little updating.

It has a large graceful foyer flanked by twin, curving staircases to the second floor that may have inspired Fitzgerald to write in Gatsby, “There was a ripe mystery about it, a hint of bedrooms upstairs more beautiful and cool than other bedrooms, of gay and radiant activities taking place through its corridors and of romances that were not musty and laid away already in lavender but fresh and breathing and redolent of this year’s shining motor cars and of dances whose flowers were scarcely withered.

“It excited him that many men had already loved Daisy – it increased her value in his eyes. He felt their presence all about the house, pervading the air with the shades and echoes of still vibrant emotions. But he knew he was in Daisy’s house by a colossal accident.”

It’s not likely that in those days Fitzgerald spent much time in the big house’s kitchen – that was for servants. The kitchen is large and functional but not glitzy by today’s standards. The room is compartmentalized into a kitchen area and a large walk-through pantry. New owners might want to add granite countertops and hand-painted tiles, some Viking appliances or a center island with imported lighting.

For special occasions, Reilly says his family used the enormous adjoining dining room, with its hand-painted walls and, speaking of imported lighting, a chandelier that family lore says came from the ballroom of Scottish Lord Hamilton’s castle. The castle was demolished shortly after the King home was built and a visiting Hamilton family member told Reilly the chandelier looked familiar.

Reilly remembers that he was also fond of the expansive sunroom at one end of the first floor. He’d play the radio there and do his homework, just inches away from the porch that inspired Fitzgerald’s description of the meeting place for Jay Gatsby and Daisy.

That back veranda, now in need of some expensive wicker furniture, might have inspired this description in The Great Gatsby:

“Her porch was bright with the bought luxury of star-shine; the wicker of the settee squeaked fashionably as she turned toward him.”

Despite the home’s elegance and expansiveness, Reilly thinks the family’s favorite room was the library, centered off the foyer, rich with bookshelves and open to the back veranda to offer a perfect view of the Judson sculpture.

Reilly hopes that the new owners will appreciate the home’s history, but especially its grace.

“I think what makes this house exceptional is the grace of it,” he said. “It has always struck me as an unusually graceful home.”