I have a confession. I was a member of a secret society in the 1970s. It was called 'The Fireball Club' and was based around a spy character from 'Bullet' comic. We had code books and Spy Wallets with charming instructions on how to disable an 'enemy'. These included crushing their insteps with your heels and elbowing them in the face. There was also an elaborate manoeuvre for freeing yourself when an attacker has you by the wrists. (I've still never heard of anyone attacking someone by holding them by the wrists.)

Then there was the plastic medallion you had to wear at all times. I did – and regularly got my backside kicked for looking like a prat. Fireball was a moustachioed, big-haired hunk of '70s manhood. I was not.

When it was revealed that the actor he was based on (Peter Wyngarde) liked hanging around public toilets, myself and my friends buried our wallets around the back garden.

Ah, nostalgia. When I look back on my childhood I often have to suppress the desire to wedgie myself. That said, we've all done things or joined some club as a youngster we wouldn't associate with now.

Eamon Gilmore may have a few clubs in his past he'd rather forget about too. Last week, he told Marian Finucane that he couldn't recall whether or not he was once a member of Official Sinn Féin. Thankfully, historian Brian Hanley has a better memory than Gilmore. He says the Labour leader was in UCG's Republican Club – the student wing of OSF – in 1975.

Funny that. I'm pretty sure I would remember if I had been a member of a party with 'Sinn' and 'Féin' in its title. Some may write this off as an inconsequential memory lapse by Gilmore. It wasn't. Was he re-inventing his past as Brian Cowen later accused him in the Dáil?

Gilmore has been getting a very easy ride lately. The rise in his popularity is based on the perception that he is untainted by a political system that has produced opportunist Mé Féiners like Ivor Callely. He's seen as a paragon of social democracy – which, arguably, he is.

His journey to paragon status began in the 1970s, when Official Sinn Féin believed that all-Ireland unity could be achieved through Communism. It sounds far-fetched today, but this was during the Cold War when students had posters of Che Guevara on their walls, wore berets and carried copies of The Communist Manifesto. They shouted slogans like "Power to the people!" and other unrealistic rubbish. Rubbish that was understandable at the time because it was idealistic.

Forty years on and Gilmore appears to be burying his past. Why? Is he afraid that by association with the words 'Sinn' and 'Féin' he will isolate middle-class voters? Does he think they are that shallow and undiscerning?

Gilmore was always anti-Provo, but he should study the career of another former radical Republican, Martin McGuinness. Last week, he addressed the Conservative Party Conference. This was akin to seeing Margaret Thatcher playing the fiddle at the Fleadh Cheoil. It shows how far he and his former adversaries have moved away from their past. We know his bloody background, yet we accept him for what he is now: a good deputy first minister. The public knows that a radical 'past' can be atoned for by a meaningful, democratic 'present'.

In Brussels, we're represented by a politician who was interned in the Curragh for IRA membership in the 1950s. Proinsias De Rossa MEP has proved that 'once a radical' doesn't mean 'always a radical'.

The transition from radicalism to mainstream should always be acknowledged. It shows that change is always possible. It proves that the political system, while producing pond-life like Ivor Callely, can also turn extremists into democrats.

Gilmore's journey from radical to centre-left has given him an insight that other careerist democrats don't have: he knows the value of pragmatism. So do the Irish electorate. Hiding his former beliefs just insults our intelligence. His 'memory lapse' on Marian Finucane's show has given some weight to his critics' assertion that he's all image and little substance. That he's too concerned with soundbite politics. That's a deeply depressing thought, as he may be our next Taoiseach or Tánaiste.

The most worrying aspect of his amnesia is that it hints at a level of dishonesty. If Gilmore is not being 100% straight now, what will he be like in power? Gilmore must be honest about his misguided, if idealistic, history. We must be able to trust our leaders again. If he can't be straight about his past, how can we expect him to be honest about our future?

dkenny@tribune.ie