Mathew Sandblaster-Trogg has not stopped bouncing since 1972, when his parents, Michael and Millicent Sandblaster-Trogg, bought him a pogo stick for his eighth birthday.
"He was thrilled to pieces when he unwrapped it all those years ago," recalls Mrs Sandblaster-Trogg. "He'd been going on about it for weeks beforehand, so there would have been hell to pay if there hadn't been one waiting for him, all trussed up in coloured paper, when he came downstairs on the morning of his birthday. I still remember how his face glowed as he frantically tore the wrapping from it."
Young Mathew was so pleased with his new toy that he spent the rest of the day playing with it. And through the night. And the next day, the rest of the week, the month, the year ... And now, thirty years later he's still bouncing.
"To be perfectly honest with you," Mrs Sandblaster-Trogg admits, "I think he's probably overdoing it just a little bit now."
He's a freakin' nutter
Her husband is slightly less tolerant of their son's unusual behaviour.
"He's a freakin' nutter," he opines. "Bounce, bounce, bounce - all the bleeding time! We can't lead a normal life - with this steaming great pillock leaping about all over the place.
"People won't visit the house anymore. All our friends have drifted away. The neighbours won't have anything to do with us, and I've been refused membership to the golf club five times. FIVE TIMES! I hardly think that's a coincidence.
"I was a dentist for forty years - a professional man. A respectable man. I've got a holiday cottage in Cornwall. There's a brand new Volvo in the garage. I once met Rex Harrison, for heaven's sake, and if that isn't sufficient acknowledgement of my status as a pillar of the community, then frankly I don't know what is."
"I think what my husband is trying to say," intercedes Mrs Sandblaster-Trogg, "is that we feel that Michael really ought to have grown out of this obsession of his."
"What I'm saying is that our son is an arsehole," Mr Sandblaster-Trogg is quick to correct her. "Do you know, we have to resurface the drive every six months. And the repairs to the ceilings inside the house are threatening to bankrupt me. Up and down, up and down, all the bloody time. I'd have kicked the little bleeder out years ago, but I just can't catch the bastard."
The pogo stick was a complete write-off
Nevertheless, thirty years of almost continuous bouncing represents a significant achievement - even if no one can agree what its significance is.
We say almost continuous since, despite his best efforts, Mathew Sandblaster-Trogg has fallen victim to a number of unfortunate interruptions over the years. These have been mostly mechanical in nature. The average pogo stick is simply not designed to tolerate years of continuous use, and inevitably failures occur. Spring fatigue, shaft rot and piston blockage are the most common problems, though it is not unknown for major blowouts to take place.
It was just such an eventuality that unexpectedly propelled Mathew four hundred yards up his street in the spring of 1985. Ballistics experts called to the scene agreed that he would have travelled much further, had he not had the good fortune to collide with a 32-year-old catering manageress who was spending her lunchbreak in the local park. On that occasion the pogo stick was a complete write-off (so was the catering manageress) and Michael had to wait two days for a replacement.
Up and down, up and down
"He was very restless during that time," Mrs Sandblaster-Trogg tells us. "He was very fidgety, nervous - sort of jittery. He spent most of his time in his room, sitting on the edge of his bed with his eyes just going up and down, up and down.
"Speaking personally, it was lovely just to have him in one place for a change, rather than springing all round the house, but I could tell he really wasn't happy. He seemed lifeless, you know. Somehow the spark had gone from his eyes. Even my husband's attempts to cheer him up didn't seem to lift his mood." She nudges Mr Sandblaster-Trogg in the ribs. "Isn't that right, Michael."
Mr Sandblaster-Trogg nods sombrely, then casts his eyes skywards. "Though heaven knows why I bothered," he mutters. "Took the little sod fishing, didn't I. Thought it would bring him out of his shell a bit - you know, man and nature in harmony, that kind of stuff.
I was wasting my time. All the stupid little prick did was jump up and down in the water - splashing about and frightening the trout. In the end he got bitten on the arse by a pike and ran screaming all the way home. Me, I didn't stop laughing for a fortnight - it's the only half-decent thing that boy has ever done."
Specially designed by Ferrari
To date, Mathew has got through twenty-five pogo sticks. His present model has been specially designed for him by Ferrari, and uses the same technology currently employed in Formula 1 racing cars.
"His big ambition is to compete in the British Grand Prix," says Mrs Sandblaster-Trogg. "He believes that whilst a pogo stick may not be able to beat a Formula 1 car on the straight, he can easily out-manoeuvre them on the corners.
But, to be honest with you, I'm not comfortable with the idea. It could be very dangerous for him out there on the track. He could get seriously hurt."
"We live in hope," remarks her husband.