It has been a revelation to find out exactly how many people Tom O'Gorman knew. I was aware he had a wide circle of friends and acquaintances but not that it ran into hundreds upon hundreds.
Apart from Ireland, he had friends in America, Italy and Britain. Come to think of it, he was born in Scotland and I used to teasingly tell him he was really Scottish. In fact, he was a very proud Irishman.
He was even more crestfallen than the average rugby fan when we lost to New Zealand recently. It was like he had lost personally. He was absolutely over the moon when we won the Grand Slam for the first time in decades in 2009.
But to return to his friends, one after another has posted moving tributes or memories of Tom on both his and their own Facebook page including people who had diametrically opposed politics to Tom's. Some remembered him from his days in UCD, a place he adored.
One friend, a member of the Labour party, wrote: "Tom O'Gorman was a man I rarely agreed with politically, but he was always friendly and a gentleman, even when we stridently disagreed with one another. To think that he died in such a way is appalling. I am quite shocked."
Another person he knew from his time in UCD posted: "Tom was indeed a gentleman, kind, decent fellow. I did not always share his political views nor indeed his religious ones. . . I always liked him personally, it was hard not to. . . He is part of my great memories of my UCD student days."
Unfortunately, it is a very human trait to see your political opponents simply as political opponents and nothing else, especially if you never meet them socially. This is dehumanising, of course. We need always to remember that those we are opposed to politically and ideologically, even if they are completely at the other end of the spectrum from us, are fellow human beings.
Twitter, which is often a cesspit, put aside ideological differences this week and simply recognised that something mind-bogglingly awful had happened to Tom. I only saw one tweet that gloated over his death and I sincerely hope Twitter will block the person responsible.
On Tuesday night, a prayer vigil was conducted for Tom in St Teresa's, Clarendon St, in Dublin city centre. The choice of venue was apt because Tom often went there after work.
Hundreds turned up. I didn't recognise the vast majority of them, which again is testament to all the people Tom knew.
It was also indicative of the fact that he was anything but a loner. He was always seeking people out.
I remember on occasion when we were walking down the street together he would stop and have a quick chat with a homeless person he had gotten to know.
Tom has been described in various outlets as "deeply religious". But that can be misleading because it can easily give the impression that he was a 'Holy Joe'. Nobody who knew him would ever call him that. He didn't wear his religion on his sleeve and he wasn't in the least bit pious in the worst sense of that word.
He had an offbeat sense of humour. On the wall above his desk he had pinned various pictures and posters that illustrated it. My favourite was the 'National Sarcasm Society', which said: 'Like we need your support.'
He also had Martin Luther King's 'I have a dream' pinned above his desk, showing another side of him.
On his bookshelf he had numerous books dealing with politics and history. He had 'The Blair Years' by Alastair Campbell; 'India After Gandhi'; and 'A History of Modern Russia' among others. They illustrated his range of interests.
I've since discovered that he had different friends who reflected his different tastes. He'd talk about rugby and football with people who shared those interests. He talked about his musical tastes with some, and films with others. Obviously, he loved to talk about politics and he knew a lot about ordinary, day-to-day party politics.
His interest in politics extended to Britain and America and he had a lot of American friends. Some of them have organised a memorial service for him in Washington DC. He would have been enormously touched by that.
He would also have been very touched by Tuesday night's vigil and the excellent tribute that was paid to him by his long-time friend, Joe McCarroll. What was notable at the vigil, incidentally, is that there wasn't one word of anger directed at his presumed killer. The only person on people's minds was Tom.
For all who knew him, the last few days have been utterly surreal. It is very hard to absorb the enormity of the evil that befell him.
The whole nation is shocked by it, and not just Ireland. My sister in New Zealand heard it reported there because Tom's death was so uniquely horrific.
To be honest, I'm not really sure how you process something like this. What happened to him is so shocking it is almost uncharted territory. However, everybody who knew him has happy memories of him. Thankfully, these memories will eventually supplant in their minds the terrible manner of his death.