At the end of 1986 my sabbatical was over and...and I was still working on this... this book, 3:16, on weekends but it was back to my normal, you know, my normal professor life. Of course I get to Stanford and I plunged in as always and resumed teaching my classes and... and I had great graduate students and... however I was having almost no time to work on The Art of Computer Programming.  And I don't know if... if any of the people watching this also go on their sabbaticals but one thing that... that happens when you get back home is people keep asking you, 'Oh, aren't you glad to be back home?' And they kept asking me this for the... for the next year and... and the next year after that and I, you know, I would always smile and say, you know, 'Yes', but really I didn't feel so... quite so... so good to be back home because I wasn't getting anything done on The Art of Computer Programming. And time... time is clicking here, I'm 50 years old, I've got lots of work to do yet on The Art of Computer Programming. So at this time I'm 50 years old in 1988, so, like I... like I go through a whole year and I'm making two days of progress on The Art of Computer Programming.  At that rate how long, you know, I'll have to be 150 years old before I'm done writing the book. So... so I decided really this wasn't a sustainable situation anymore, what I would have to do is figure out how... what... how to spend the rest of my life and finish The Art of Computer Programming. So I came to a reluctant decision in the summer of 1988 that I should retire very early from Stanford and I should devote the rest of my time to finishing what I really do best, which is The Art of Computer Programming. You know, I... since 1962 I've been gathering... gathering tens of thousands of... of papers, read them, made notes on them, organized this, it was all things I think are really important to have in a book and I wasn't having any opportunity to really get that stuff ready. So I wrote a letter to our chair of our department and I said, Nils I would like to retire... I... I would like to retire as of January 1 1990, a... a year and a half from now... you know, a year and some months from now, and I don't feel right about... I... I don't like the idea of a professor who's going to just write books and not... and not do the rest of the... the job that... that you do at a university including not only teaching and advising students and serving on committees and... but also fundraising and... and... well many other... you know, correspondence, answering people's queries. And I said... so I... I go and see... see why... but still I have to write The Art of Computer Programming or I'll never really be happy and I have to... and it's going to take me many years of work, so I'm asking that you find a replacement for me at Stanford. I wouldn't want to take a salary for something... for... for not doing the work of... And then... so we met with the... with the Dean and the Provost and they, you know, first tried to convince me to just carry on as I was and then I said no, really, this book is a special thing that I think is... it makes... makes it different from all the other hundreds of professors that you've got, you know, this book is a little bit more important than all the other professors' books, etc., I'm telling them. Well, the Dean checked around and he... and he... with some people and he said well, the books are pretty good anyway so... so he thought maybe he could get somebody to... to endow a chair that... by which I would... I have only the responsibility to write the books. I said I didn't, I know... I'd rather get somebody else to do... to do what I was doing instead and then let me take early retirement. Well, early retirement at... at age 52 was not possible.  What... what was possible was that I could take a leave of absence for three years until I was 55 and then I could retire. But that's what happened... January 1, I... I didn't anymore have to serve on committees or... or raise money. On the other hand I deeply regretted not being able to teach anymore and... and similarly advising graduate students - that was something that... that has always been a special joy. I... in order to... in order to account for the teaching we... we decided that I would give... I would give semi-regular lectures called Computer Musings, which would be open to the public and anybody could come - no credit would be issued for these lectures - but... but I would talk about whatever I thought was cool to talk about and something that wasn't covered in Stanford's curriculum, and... and periodically - we were going to shoot for once a month - I would... I would do these lectures. And that... and I could have a title and that's great, I was... I don't know if I'm the only Stanford professor who was able to choose his own title but I became Professor of The Art of Computer Programming, and that's my official title. And that's The Art with a capital 'T'. And that didn't mean I have a salary but it meant that I had a nice title and very nice stationery and... and I became Professor Emeritus of The Art of Computer Programming, officially then when I was 55 years old. This gave me, you know, medical... medical insurance and... and all of... and also I have, in fact, a secretary and an office and... and all the library access and everything I needed to do the... the books right. But... but I'm not in anybody's... anybody's inner loop where they're depending on me to... to do something.  I can... I can take a day like today and... and never show up and nobody will... nobody will be the worse.