Dáil Sketch / Frank McNally: There were two dramatic conversions in the Dáil yesterday. On Tuesday, asked if the Government would amend legislation to exempt the Band Aid 20th anniversary CD from VAT, the Taoiseach responded in terms that were loosely interpreted as "Bah, humbug."
Twenty-four hours later, presumably after being visited by ghosts, he changed his mind.
Mr Ahern was limping heavily when he arrived for Question Time, causing Enda Kenny to speculate that he'd had "a kick from a horse". The truth was more bizarre.
The Irish Times later learned that Mr Ahern damaged a ligament on Monday while jogging, as part of the annual pre-Christmas fitness drive that sees him give up beer for November.
On Tuesday, he attempted to cure the injury with a "vigorous walk", which is not the recommended treatment for damaged ligaments. So a week into his fitness drive, Mr Ahern was already worse for wear.
His staff privately confess to dreading this month, and yearning for December, when their man has less time on his hands.
But during questioning on the Order of Business, the most plausible explanation for the Taoiseach's injury was that he had fallen out of bed in fright overnight, after the ghost of Bob Geldof past appeared to him saying "Give us your f***ing money!"
At any rate, he paid a warm, unprompted tribute to Mr Geldof, before announcing that the Government would make a donation to Band Aid equivalent to the VAT raised by the CD and DVD.
Labour, which had first raised the issue - reacted like Bob Cratchit's family on receiving a turkey. The childlike joy in Joan Burton's eyes was particularly touching.
"Does this mean Christmas has been reinstated?" she asked Mr Ahern, who just smiled, as if to say: "Ho Ho Ho!"
In the day's other dramatic incident, Sinn Féin's Caoimhghín Ó'Caoláin actually told a joke. During an exchange about Irish-American relations, he announced that he "would like to share a light note" with the Taoiseach.
Whereupon, he suggested that the US presidential election had hinged on the high numbers of Mayo emigrants among Ohio's Irish community. "After the All-Ireland victory, they couldn't bring themselves to vote for Kerry," he quipped.
"Very good!" said the Taoiseach, who nevertheless seemed unsure on how exactly to react.
It's too early to say whether the joke marks a deliberate change of direction for Sinn Féin, which has not been known for its sense of humour and would probably need a special Ard-Fheis to approve the policy.
But it seemed like a step in the right direction.
It wasn't all pre-seasonal good-will yesterday.
When Mr Ó'Caoláin urged the Taoiseach to crack down on schemes that allowed rich people to avoid tax, Mr Ahern mischievously agreed with him. "Eliminating scams in cigarettes, petrol, and alcohol" would help the Exchequer enormously, he said.
This did not go down well.
Despite the new humour policy, Sinn Féin still resents suggestions that there is anything funny about the party's money or its fundraising activities, and Mr Ó'Caoláin angrily accused Mr Ahern of performing "political handstands".
Which, given the Taoiseach's injuries, may be the only form of exercise now available.