Many people would agree with the Elton John lyric that "Sorry seems to be the hardest word'' – but Sean Kelly isn't one of them. The retired terrorist had no trouble saying sorry for bombing Frizzell's fish shop. And that's hardly surprising, since his apology was meaningless.
Kelly was not sorry for collecting a bomb from his murderous mates in the IRA on an October day 20 years ago, or for transporting it through the streets of Belfast on that busy Saturday afternoon.
He did not apologise for bringing it to a Shankill Road full of innocent men, women and children. He did not say sorry for taking the bomb into a fish shop, knowing it was soon to explode. He apologised only for the fact that this operation went "tragically wrong''.
So he was sorry only that the bombing did not have the outcome intended. It was aimed at loyalist gangsters, as bloodstained as himself, who unleashed terror on innocent Catholics in retaliation.
But the UDA men weren't at Frizzell's and, instead, the bomb killed nine shoppers – including two children.
It also killed Thomas Begley, another bungling bomber, whose death on "active service'' Kelly was commemorating when he issued his apology.
Kelly described his fellow killer as "a good, sound, brave, solid IRA volunteer''. No wonder his apology was rejected by the people of the Shankill Road.
Better no apology than one which – as an uncle of one of the victims said – rubbed salt in the wounds.
Relatives of the eight people murdered in the Greysteel massacre the following week may also question Torrens Knight's sincerity when the killer said at the weekend: "My thoughts are with them. At the end of the day, it shouldn't have happened. It was a terrible thing."
Martin McGuinness likewise apologised for the fish shop bombing, but his apology was of a different order. The tragedy, he said, was "caused by republicans''.
He did not "seek to hypocritically distance myself from the loss of so many innocent lives on the Shankill''. He accepted that "the reality of republicans' responsibility must be acknowledged''.
But it is not only the forthright language which differentiates Mr McGuinness's apology from that of Sean Kelly. The deputy First Minister was not accounting for actions in which he had a direct hand, or part. He was speaking as a figurehead of republicanism, expressing remorse for things past and, more so and more importantly, expressing his desire for a better future.
Some will dismiss Mr McGuinness's apology as hypocritical, given that he was once an IRA commander. They may be right, but that criticism misses the point.
The deputy First Minister – unlike Kelly – was offering a proxy apology on behalf of the republican community.
He was extending a hand of friendship to the unionist community.
What matters is the genuine nature of his goodwill, not the quality of his remorse.
I doubt if David Cameron was really remorseful about Bloody Sunday when he apologised three years ago for "the unjustified and unjustifiable'' killing of 14 civil rights marchers. After all, he was only six when it happened.
Tony Blair was not accepting personal responsibility for the Famine when he apologised for the actions of "those who governed in London'' in the mid-19th century.
And Taoiseach Enda Kenny was not accepting personal liability when, in February this year, he stood in the Dail with tears in his eyes and apologised to the women and girls who had been incarcerated in the Magdalene laundries.
Mr Kenny expressed "deep regret'' on behalf of "the state, the government and our citizens''. If we parse his words too carefully, this will be seen as a fairly meaningless mantra.
But Mr Kenny, who had no involvement at all in the Magdalene scandals, did not intend his apology to be assessed in that exact way. He was offering comfort and consolation to the women; telling them that a society which had once shunned them now accepted that they had been done a grievous wrong.
The women understood and accepted Mr Kenny's comments. They already knew they had been wronged. They already knew they were victims, not culprits.
But the affirmation afforded by Mr Kenny gave formal recognition to their position and allowed them to start putting the awful events behind them.
Several of the women have said they would also like an apology from those directly involved. They would like the religious sisters who persecuted them to explain themselves and account for their behaviour.
No such statement has been forthcoming and, perhaps, that is just as well, for such a personal apology would inevitably be accompanied by some element of justification, which is not what the women want, or need.
The proxy apology, issued on behalf of a wider group, is an oil that makes the wheels of decent society turn more smoothly. We should accept such goodwill gestures in the spirit intended.
The personal apology is a different matter. If sincerely meant, it is a powerful balm that can salve many wounds. If not, it will hurt more than it heals.
So unionists would do well to say thank you, Mr McGuinness – apology accepted. But, no thanks, Sean Kelly.
Sorry may be the hardest word to say, but it's also very hard to listen to when you know it means nothing at all.