Mike Short believes he has the secret for staying forever young - sort of.

He has not managed to mix a magical elixir of youth.

Instead he encourages people to stay eternally 21 - in spirit, at least - by celebrating and treasuring the year they reached that landmark age.

Mike, from Goring, is the founder of Potato Academy - with Potato standing for People Over Thirty Acting Twenty-One.

In real terms he is 46 - but in his mind he remains 21, the age he turned in 1978.

That was the year he met his future wife Sue - and enjoyed their first dates to the sound of Never Let Her Slip Away by US singer-songwriter Andrew Gold.

He came up with the idea of Potato Academy while taking a bath - inspired by the love of nostalgia shown by TV shows such as I Love The Eighties and web site Friends Reunited.

He spent months researching the key events, names and pop culture references to go with each year remembered at www.potatoacademy.com When he first launched the site last year, it was open for anyone aged between 30 and 60 but now he is encouraging people aged up to 75 to join in.

Mike, who runs the firm from an office in Ferring, said: "Traditionally 21 is meant to be the year you're given the key to the door, only to find it unlocks the room marked Now Get Old.

"All you have to look forward to are those landmarks of turning 30, 40, 50 and so on.

"But if you speak to many people over 30 you'll find they refer to themselves as 21 - or at least wish they still could.

"The year you're born is obviously important but you won't remember anything of that. What you were doing when you were 21 stays with you more vividly."

Mike spent his 21st birthday in April 1978 on a business trip to northern Italy, where he stayed in mountains near Lake Como.

He said: "We mixed business with some sight-seeing. But like most 21st birthdays, mine passed in a bit of a blur.

"What I do remember is we were there around the time the politician Aldo Moro was assassinated so there was a lot of fuss and coverage about that."

More memorable were his first dates with future wife Sue, the sister of one of his friends.

He said: "Never Let Her Slip Away by Andrew Gold was a big hit at the time. It always seemed to be on when we went out and it's stayed a special song for us."

The pair married the following year and will celebrate their 25th anniversary in September.

Mike believes he has changed little since the late Seventies.

He said: "I still seem myself as 21 - well, I still play squash at least.

"People may look in the mirror and see a few grey hairs, a balding head or wrinkles but it's only natural to want to stay feeling like a young person."

Mike, who used to run his own marketing consultancy in Buckinghamshire, moved back to Sussex last year to launch Potato Academy as his full-time devotion.

He works alongside four others - including Sue as distribution manager - although the web site also lists the head of the academy as a character called Professor Edward D Spudd.

Mike said: "We'd like to get more contributions from people. Things like songs and films spark off memories for people.

"I've had people telling me how much they appreciated being reminded of things they had forgotten about."

Logging on to the site is free.

The firm is financed through the design and sale of greetings cards, badges and montages dedicated to the year someone turned 21.