By a neat coincidence, one of the year's less heralded anniversaries falls in October, just four weeks after Scotland's referendum.
To the faint surprise of some of us, half a century will have elapsed since Labour won power and ended, in the catchphrase of the day, "13 years of Tory misrule".
In fact, it wasn't much of a victory. The Conservative Party and their new leader, Alex Douglas-Home, were in a familiar mess: exhausted, scandal-ridden, toff-afflicted and bereft of ideas. The Old Etonian in charge was easily and often satirised as out of touch, a figure better suited to grouse moors than to the new "meritocratic" Britain. Yet Labour barely scraped home.
Harold Wilson only got into Downing Street, in fact, because a large part of the Tory vote migrated to the Liberals. Despite their modern, media-adept leader and their national economic plan, Labour's support scarcely improved - by 0.3% - from the hiding it received in 1959. The party took office with a parliamentary majority of four.
In late 1964, Labour didn't have many laurels to boast of, but they did have a manifesto that still makes for fascinating reading. "The New Britain" assured its readers, for example, that "the ending of economic privilege, the abolition of poverty in the midst of plenty, and the creation of real equality of opportunity" had become "immediate targets of political action".
Steel needed to be nationalised. Tory plans for the "restoration of a 'free' market economy in Britain" needed to be undone. House prices were "soaring"; there was "growing stagnation, unemployment and under-employment in large parts of the North, Scotland, Wales and Northern Ireland", allied to "a drift of work and people to the overcrowded London and Midland regions". This wouldn't do.
Worse, there was in Britain "a pervasive atmosphere of irresponsibility … a selfish, get-rich-quick mood, in which the public interest is always subordinated to private advantage". Public money was being "lavished on wasteful military projects" while "austerity National Insurance benefits" imposed "poverty standards on the retired, the sick and the unemployed".
Labour - promising "fresh and virile leadership" - said benefits had "fallen below the minimum levels of human need". They abhorred the "burden of prescription charges on the Health Service" - abolished by Labour in 1965, restored by Labour in 1968 - but also worried over "the problems of leisure in the age of automation". Scotland got a mention. That's not a figure of speech.
Half a century is enough of a span to allow talk of history. The historical part relevant to Labour could be summed up in two words: next time. For five decades that species of hope has kept the party more or less alive. It has been 50 years of "next time". Once Labour defended their achievements, now they are complicit in their demolition. The refrain stays the same: next time.
Ed Miliband might get a majority, perhaps even a majority greater than four. Stranger things have happened. But here's 50 years witnessed since Harold Wilson first flickered across the screen of a Murphy telly to back a simple claim: with Labour, next time never comes. The contemporary party's embrace of austerity and all it entails guarantees that a half-century streak will not end in 2015.
For Better Together to prevail in Scotland's referendum, you would have to believe otherwise. You would have to believe in Labour's "progressive case" - while, confusingly, telling Scots that their progressive reputation is a myth - to justify a majority for No. For Labour voters, that key part of the electorate in this contest, the choice is plain enough: independence or "next time".
That being the case, reminders of last time are problematic. As opinion polls narrow, demands by fretful Unionists for more interventions by Labour's "big beasts" from yon time court a risk. The reappearance of some who are otherwise home free in the Lords might serve to remind voters what happened to "next time" last time. Faces from the reactionary past fronting a rejectionist campaign are not synonymous with progressive ideals.
Tories are obtuse about this. Some are sufficiently self-aware to realise that packing David Cameron or George Osborne off to Scotland is counter-productive. People who want you to believe that Scots are no different from folk elsewhere haven't forgotten election results. In solidarity with Stevenage (or whatever) Scots don't elect many Tories and barely notice Ukip. Conservatives therefore define Scotland as Labour's problem and grumble when the problem isn't solved.
The attacks on Alistair Darling arrive with each new set of polls. This week's anonymous Conservative genius observes of the former Chancellor: "He's a middlingly competent accountant with zero charisma. You never see him. Where is the big figure to lead the campaign and take the fight to Salmond? It's just dismal." Set aside the (ignorant) insult to an advocate. Such Tories are also arguing, it seems, for Mr Darling to be dumped in favour of Lord Reid, John Reid as was.
What this would achieve isn't clear, though the reactions from Lord Reid's Celtic Park constituency would be interesting. It doesn't resolve the Unionist problem. Setting aside the ineffable incompetence of the scarcely representative CBI Scotland, Better Together has plenty of those "big" figures available. What it lacks is a Labour politician who has not spent a career promising "next time" and falling - let's be polite - a little short.
Gordon Brown exemplifies the problem. In a speech in Glasgow yesterday he contrasted two possible futures for Scotland. In one glimpse into the crystal ball he saw an independent country struggling to support pension liabilities - nothing to do with actual costs - while deprived of what he effectively alleged to be a UK subsidy at a time when pensioner numbers are rising.
The remarks were disputable, to say the least, but that wasn't the real difficulty for Better Together and Labour. Gordon Brown on pension security? The man who, as Chancellor, had to invent the annual winter fuel allowance in 1999 when pensioners decided that a 75p increase was not the stuff of dreams? The man who removed the tax credits on company dividends for pension funds and, if you believe his critics, destroyed occupational schemes?
Labour have spent half a century promising "next time". Now it offers more of the same and a few words from a specialist in such promises. Better Together wants to attack Alex Salmond for proposing to cut corporation tax if he is elected after independence? You could make a good case. But you then have to pray that no-one remembers Mr Brown cutting the same tax by 3% in 1999.
In those days, he was one of the big figures in a New Labour government swept to power by the old, desperate belief that next time would be different. Just like the last time. Now Scots are asked to believe it once again because that, supposedly, is what true solidarity means. Instead, half a century of experience says it's what credulity means.
Harold Wilson was the first politician whose name ever stuck in my child's mind. At that age, you can be persuaded to believe just about anything. But that was long ago, in another country.