I wrote the S-matrix paper over Christmas. Because the S-matrix paper needed a lot more work. It was a much more ambitious programme. It meant proving the whole series could be done all the way. The original radiation theory paper was only to second order and I had to prove that everything worked to all orders of perturbation theory and so on. So that took a while.

[Q] But it was already in your mind to try to do the general problem?

Yes. It became clear that it was the S-matrix that we were talking about, so then, it was in probably October, November, December, I worked out the S-matrix theory and then wrote it up over Christmas, and I remember going to a tea party with Wigner - I never really got to know Wigner well, but he invited me to tea which was nice and his wife was very hospitable. I think, again, Cécile and I were invited and I was going out with Cécile a lot at that time, although I never had the slightest romantic feelings about Cécile but she was such a great person, so we got along very well. Anyway, so we went to tea with Wigner and just as we were walking in at the door, suddenly I realised that divergences could overlap, that the whole S-matrix technique depended on divergences not overlapping, but in fact they did overlap and so the whole thing was no doubt completely wrong. So I walked into Wigner's house with this sudden...

[Q] Insight...

Realisation the whole bottom had fallen out of it! So I was rather inattentive during the tea party. And then, afterwards, I came home and tried to work out the overlapping divergences but I never really got them straight, so it remained a loose end. So I wrote the S-matrix paper without really settling the problem of overlapping divergences, which afterwards Abdus Salam actually did. So I left it for him actually to clean it up, and so it was a matter of faith whether you believed that it was going to work. But I wrote the paper anyhow and published it because I couldn't deal with the overlapping divergences. They really were very hard to do. And then, so after that paper was published, then suddenly I became famous and my life changed, from ever afterwards...