There are people who live and breathe the paramilitary life. You think they are only really republicans, or loyalists, when they are among their associates in the pub, when they are marching in a parade, or commemoration, when they are drilled in prison, or standing at the open grave of a former comrade. That may be true of some, of most, for all I know.
In recent years, I have interviewed several retired IRA men, most about the same age as myself.
Some of them live in houses that are bedecked with paraphernalia. They will have a Celtic cross made out of matchsticks by a former prisoner. They will have pencilled portraits of some of the dead on the walls. Some have framed the gloves and flag that were set on the coffin of a forebear for an IRA funeral. And some have none of that.
Twice, in recent times, when I called men who held senior positions in the IRA in Belfast and Londonderry and asked for an interview, I got the same answer: "You'll have to be finished by two for I'm picking up the grandchildren from school."
So, some of those who did the killing, or spent years and years in jail, live out relatively normal lives now, despite what they have been through, and some are so wholly immersed in their cause, have so much of its history imprinted in their nerves, flowing in their blood, that they do not actually have another life, or another self who is not that old militant.
That person's living-room will be garnished with IRA memorabilia. It will be a shrine to the dead. He may even wear a little medallion around his neck with the engraved image of Bobby Sands, or Mairead Farrell, on it, like the holy medals we wore as children when the icon was the Virgin Mary, or St Christopher.
This level of adornment is not as bad as it used to be. A few years ago these people lived with conspicuous security.
I was in the home of a republican family in Cullyhanna once and saw the wrought-iron grill at the foot of the stairs, the shuttering that secured the front door.
In another home, in Belfast, I saw cast-iron shutters on the windows and the bullet strikes in them. They stood open to let the sunlight in and two little girls in school uniform sat on the sofa doing their homework together.
And yet that family seems not to be involved in republican politics now.
Victor Notarantonio, who died of cancer this week at the age of 67, had republican culture embedded in him. Its history, down the generations, was his own family history. And there are many others like him.
Victor Notarantonio's father, Francisco, died at the centre of one of the most complex and revealing dramas of the Troubles period. He was 66 years old, in bed with his wife, Edith, when gunmen stormed into the house, crashed through the bedroom door and shot him as he rose with his hands up, hoping to surrender.
Immediately, there were allegations of collusion. The attack had been abrupt and thorough, right in the heart of Ballymurphy, not ground on which the UDA was normally comfortable operating. And the family said that intense Army activity beforehand had cleared away, as if the killers were being given free access to their target.
Now, it is widely accepted that Francisco was killed as a substitute for Freddie Scappaticci, the Army agent 'Stakeknife'. Another agent, Brian Nelson, had directed the killers towards him.
Scappaticci was an indispensable asset to the Security Service. He was the head of the IRA's "internal security unit", which interrogated and executed suspected informers and he had virtually encyclopaedic information on the IRA to share with his handlers. He was also well-placed to protect other agents and kill off surrogates for them.
Victor Notarantonio - Francisco's son - was an active member of the Provisionals. It is said now that he was the one to kneecap Gerry Adams's brother, Liam, in the late-1970s in an act of internal IRA discipline.
After the peace deal and the Good Friday Agreement, the Notarantonios were thought disinclined to follow the agenda of Gerry Adams and those around him. The Provisionals broke their own ceasefire and jeopardised the peace process to deal with one member of that family, Joseph O'Connor. O'Connor was Francisco Notarantonio's grandson and a leading member of the Real IRA. The Provisionals shot him dead in Ballymurphy in 2000.
And, in later years, members of the family claimed that the Provisionals were trying to drive all the Notarantonios out of Ballymurphy. Many of them were involved in a feud which they said originated in a fight with a senior republican and for which some of them had agreed to leave the area for a time.
That connection to dissident republicans made Victor Notarantonio a suspect when his fingerprints were found on a mirror in the home of Denis Donaldson, after his murder in Donegal. This family name features in some of the most notorious incidents of the Troubles - and after.
Donaldson, we know, was a police informer while working in administration for Sinn Fein. He had outed himself after being warned by the police that he was about to be exposed, but he trusted IRA assurances of safety and retreated to a cottage near Glenties, where dissidents tracked him down and shot him.
Victor Notarantonio wasn't charged and he denied responsibility. He said he had visited Donaldson some weeks before; that explained his fingerprints. But it is hard to imagine that visit would have been a friendly one.
Notarantonio's father had been killed to spare a tout and here was another spared tout living in Donegal. Who knows? Perhaps they were both oblivious to the symmetry.
The question for the rest of us is whether a family that has been through so much ever gets over it. It was people with that degree of acculturation into the cause who carried it across periods of peace, like the 1960s, into new waves of activism.
That's a difference, for instance, between Martin McGuinness and Gerry Adams: McGuinness discovered his republicanism on the street when he was 20; Adams took it in with the milk on his mother's lap.
When we talk about the legacy of the Troubles, we talk about the need for justice for the victims.
We need also to ask how some paramilitaries who were through the worst were able to put it behind them and others have names that rebound down the years from drama to drama.