The BBC's Andrew Marr called it "the gathering of the has-beens" when he saw me and my drinking companions huddled at one end of the Grand Hotel bar in Brighton during September's Labour party conference. It was my first conference visit in five years, and I had bumped into Tim Allan and Charlie Whelan, who worked for Tony Blair and Gordon Brown, respectively, when I worked for Peter Mandelson.
I had just got back from California, where I spent three years training as a psychotherapist. I had lost touch with all but a couple of my old Westminster mates who formed new Labour's praetorian guard in the mid-1990s.
Marr's joke set me wondering what had happened to my generation. Start with Allan and Whelan. The first, after handling corporate communications at Sky TV, now runs a successful PR business. Whelan works as a broadcaster and journalist. I thought of 14 other contemporaries: Sue Nye, Ed Richards, Neal Lawson, Douglas Alexander, Ed Miliband (all advisers to Brown), Anji Hunter, David Miliband, James Purnell, Liz Lloyd, Pat McFadden (all Blair aides), Sion Simon (who worked for George Robertson), Simon Buckby (John Prescott), Ben Lucas (Jack Straw) and David Clark (Robin Cook). Of these, eight are still directly involved in politics, either doing the jobs they did before, or as MPs in their own right. The others work in a communications or public affairs role, like Allan, or in the political media, like Whelan.
What stands out from this survey is that not one of my old colleagues has walked away from politics and done something wholly unconnected with Westminster. Only I have that distinction, propelled from that world largely by scandal.
Is politics so compelling that nobody who has been bitten by the bug ever loses the urge to participate at whatever level they can? It seems to be. Despite the occasional brief absence to spend more time with the family, it is rare for a politician to renounce politics. From the time I was active, I can think of only Matthew Parris doing so. Why this trend?
You may suppose that it is to do with excitement and power. But, as anyone who has actually worked in politics knows, it can be unremittingly tedious; not for nothing did John Smith talk of playing the long game. Some MPs accept at an early stage that they are not destined for high office of any kind, but they stay around for ever none the less. Under the British system, real power is increasingly concentrated and therefore few politicians actually get a chance to exercise it personally.
My studies of psychology lead me to consider a different explanation. Perhaps I am drawn to it because it speaks especially to my own experience, but I think it has a wider application.
Although politics does not necessarily provide excitement or power, it does provide a ready-made identity, one where your sense of who you are is sharply defined against "the other". For anyone with an underdeveloped sense of self-esteem, this is a lifeline, providing a short cut to coherence and purpose. In the midst of all its supposed drama, politics provides a certainty that is enormously comforting.
The psychoanalyst Melanie Klein wrote that emotional health is based on resisting the urge to split - into right and wrong, good and bad. The influential school of therapy that grew up around her ideas believes that recognising ambivalence, uncertainty and doubt is the foundation of a mature psyche.
Yet politicians wallow in splits. At most points in Labour history, Alan Milburn and Gordon Brown would have been allies, occupying identical positions within its broad church. However, gangs must be constructed, because they shore up politicians' sense of who they are. The need to belong to one side is what drives the dynamic of political life, best summed up by Margaret Thatcher's infamous question: "Is he one of us?"
Adopting a ready-made political role, one that all but crowds out any other aspect of yourself (think of the monomania of Thatcher or Brown), provides identity, company and a pastiche emotional life. Because you expose your artifice only - never the "real" you - it feels psychologically safe. That explains why politicians can take emotional batterings that would floor the rest of us: it isn't, in a very literal sense, actually happening to them.
Once those who are drawn into politics have experienced that safe world, they find it hard to leave it behind. Leaving that world, as I myself know, presents you with a formidable challenge: to enter a world where you are no longer special or important, where you face up to sometimes being wrong, and where it is no longer a sign of weakness to say you are sorry.
I suspect that what ultimately matters to my old comrades is not what they do for politics, as they claim, but what politics does for them. Even if they are temporarily exiled from its comfortable embrace, they stay huddled close to it, plotting their safe return home. Few, if any, will try to make a life for themselves elsewhere.
And me? I am setting up a psychotherapy practice and studying for a second MA at Essex University. If I make a success of it and build a stable professional and personal life, I may prove deaf to Westminster's siren call.
But if you catch me propping up the conference hotel bar year after year, you'll know that it turned out differently.
Derek Draper writes for Night and Day, the Mail on Sunday magazine.