Staying in touch with family and friends

is more important than ever right now. We all know that. I am wondering how many of us realise how  important?
The Senior Cat has told me, more than once, that the thing he misses right now is my friends coming in to talk to him. I think they may be his friends as well. 
Of course, at his age (97), many of his friends are no longer with us. Last year he made a new personal telephone book. The old one was a mess of crossings out, updates and the like. The cover was falling off. The pages were dog-eared. 
But doing the job was an emotional journey for him as well. He found that "so many people aren't here any more". We reminisced about people we both knew. He reminded me of things which had happened that had been important to him. We puzzled over a couple of names that had been added - "that was the man who came to...?" and "they were the couple who wanted me to fix their...?" 
The new personal phone book is a slimmed down thing. I found the address book I had when I first went to London  half a century ago. It was written into an old school memo book, the sort we used for "mental". It had once belonged to the Black Cat for just that purpose and I had, thriftily I suppose, pulled out the used pages and then used the rest of it. There were names there I barely recognised. I know people gave me their addresses before I left but even then I had no real idea of keeping in touch with them. They were on verge of getting married and having children. Even then I knew their lives and mine would diverge. The bonds had never been strong anyway. I have the second address book now. I can see it here on the shelf as I write this. It is a bit like the Senior Cat's personal telephone book. People have gone astray or missing altogether. It was first written in the pre-internet age. Email was something we knew nothing about. 
Email should make it easier to keep in touch - if you have email. I realise that some of my friends do not have email. Others do not always think to check theirs because it is not their normal mode of correspondence.
I know I should redo the address book - but I don't want to be reminded.