At a Labour fringe meeting in Liverpool, the chairman started to make jokes about Beatles songs. Maybe the title of the next Labour manifesto could be Help! he suggested. "Twist and Shout," called out someone else. "Taxman" said a third. At which point I couldn't help calling out "Revolver".
The atmosphere at Labour conference was an odd one. The moderates were far too depressed and bemused to make all that much of a fuss. There was a middle ground of people who might be considered non-combatants. And supporters of the leader were not numerous enough.
One moment only told you how turbulent things are underneath and hinted at the struggle that may be ahead. The deputy leader Tom Watson brought the conference to its feet with a rousing defence of the Blair and Brown governments.
There was an irony here - Mr Watson did his best to bring down Tony Blair and was only marginally more loyal to Mr Brown - but there was also a message. The moderate forces in the party remain strong even if at present in disarray.
The truth in Liverpool was that the hard left has not taken over the Labour Party. It has captured the leadership, but its grip on the party machine and on constituency organisations is far less secure than Mr Corbyn's majority would lead you to suspect.
The hard left has not taken over the Labour party
The assault on Mr Corbyn's leadership was understandable - to have a party candidate for prime minister whom you can't in good conscience advocate is a terrible dilemma - but it was also foolish. The moderates were mounting an attack on the left at its strongest point. Removing the party leader is the least winnable of all the battles they could have picked.
There are, it is true, many hardened and experienced supporters of Mr Corbyn whose left politics inspires them to activism. They are ready to organise themselves in an attempt to conquer party offices and infrastructure. But much of Mr Corbyn's backing comes from people who lack the impetus for such a battle. The takeover of policy, conference, machine and parliament is thus less easy for the left to achieve than seizing the leadership. Fight the left over Mr Corbyn and you lose. Fight on anything else and you may succeed. And this may be a critical understanding for supporters of Israel to achieve.
In Liverpool, I was struck by two thoughts at once. The first was banal: We face a critical challenge more severe than we have ever faced before. One of the two candidates for prime minister looks set to be Israel's biggest opponent in parliament.
The other thought I was more surprised to have. This challenge is also an opportunity.
We Israel-supporting Jews have been losing the left for a long time. Once the left was our strongest source of support, but anti-Zionist sentiment had become so strong in Labour by the early 2000s that it contributed strongly to Tony Blair's fall from office. It had entered the left mainstream.
We have watched, despairing, as this has taken hold and not been sure quite what to do with it. Now the Watson speech shows us. The moderate left is ready to be rallied against the leader. They cannot depose him but they remain strong. They are in a state of flux, not sure what to do next, not sure what to think, not sure what the future holds.
There are few moments in politics when you can move minds and positions. Generally, people hold tenaciously to whatever they did or said yesterday.
But this is such a moment of change. We can move the moderate centre of the left back towards Israel precisely because Mr Corbyn is on the other side. People looking to define themselves against their leader - and there are many of them - are forging a new identity for themselves.
A large mainstream part of the left may be willing, for the first time in more than a generation, to move towards Israel rather than away from it.
This may seem like the moment for supporters of Israel to turn its back on the left, despairing of it. And Labour seems so far from power, why bother?
I think this would be an error. We need to think strategically. We need more things like the JLC's admirable Cable Street commemorations.
One day, Labour will again win power. If they do so as an anti-Zionist party it could be disastrous. Now is the moment when minds are open, when we can win new support. Leave it for a few years and it will be too late.