The death of Muammar Gaddafi has removed a big problem for this country's transition rulers. It has also imbued the new Libya with original sin it may regret.
The leaders of the National Transitional Council (NTC) during the months of the fight against the colonel often spoke about building a country based on rights, not revenge.
But the iconic image of their moment of national liberation is of Col Gaddafi, a man who spilled oceans of other peoples' blood, not accounting for his crimes in a court, but being set upon by fighters who killed him.
One man here in Tripoli told me he thought Col Gaddafi should have been spared to make him face justice. But everyone else I have spoken to is just pleased he is dead, and they do not care how it happened.
But if the new Libya is going to be a country of rights, then it has some questions to answer.
The most pressing are about what appears to have been the summary executions of Col Gaddafi and his son Mutassim.
But black Africans have also been rounded up as alleged mercenaries, on little or no evidence, without being given access to a lawyer.
I saw several dozen of them today being driven through Tripoli, hands bound, blindfolded with cloths of Gaddafi green, in the back of trucks with welded-on anti-aircraft cannon and heavy machine guns.
Col Gaddafi was a cruel dictator who ordered appalling acts of murder. He built a system that ran on fear and brutality.
He deserved to face punishment. The one he received was summary justice - of the kind that his own henchmen had meted out for years.
States that have been through deep and violent change tend to do best later on if there is a process of national reconciliation. Old enemies need to learn how to work together.
Maybe dispatching Col Gaddafi and his son will make that easier - or it might make the NTC's promises of fairness and forgiveness harder to believe.
Right or wrong, killing him quickly solved a problem for the National Transitional Council. The arguments about what to do with the body and where to bury it have been difficult enough.
If he had lived, there would have been months of rows about his crimes, his trial and his punishment.
And there would have been the nagging fear that Col Gaddafi's existence, and his first public and no doubt defiant appearance in court, would be a focus for the old regime's loyalists, who are now quietly keeping their heads down.
And the death of the colonel has changed the atmosphere in the capital. To get an idea of how profoundly, take a walk through Martyrs' Square in the old part of Tripoli. It was called Green Square in the Gaddafi years.
During the time in the spring and summer that Nato was bombing Libya, the square was the centre of the Gaddafi cult.
Most afternoons and evenings there were demonstrations, all with the same simple message - against Nato, and glorifying the colonel.
The rallies were not comfortable places to be. The crowd would work themselves up to a pitch of anger. On Fridays especially, thousands of bullets would get fired into the sky.
Ask someone a question and you would be surrounded by a jostling, yelling mass of people competing to condemn the West and express their love for Muammar Gaddafi.
As soon as the regime fell at the end of August, it started to change. The faces were different.
I had started recognising the noisiest regulars in the Gaddafi rallies. The new ones in what was soon renamed Martyr's Square often said they had not been to the Square for years.
As in all police states, the best thing to do was to keep your head down so as not to get noticed.
Some things do not change. Libyans are never going to be quiet when they get into a crowd.
People celebrating the death of the Gaddafis, just like his supporters, enjoy driving overloaded cars around the city at speed, as they hang out of the windows and chant slogans.
And Libyan still have an alarming love of expressing their emotions by firing into the air, though I notice they aim the heavy guns out to sea now instead of straight up.
But I have never seen Tripoli so relaxed, which should not be surprising. A heavy weight has been lifted. While Col Gaddafi lived, many Libyans could not quite lose the fear that he might come back.
But now they have seen his body. Crowds in Misrata have even lined to view it and snap it where it lies in a cold store.
Tunisians and Egyptian revolutionaries have a growing fear that they got rid of the man at the top, while important parts of the old regime stay intact and powerful.
Libyans do not need to have that fear. Col Gaddafi's Libya has been smashed. It is, really, a new beginning.
That is why they need to get the fundamentals right from the very start.