Donald Knuth is a good programmer, a programmer’s programmer.
I remember hearing a talk he gave in 1980 w h e n h e w a s a b o u t . 7 5 y e a r i n t o t h e T E X - a n d - project.
He expected to be finished soon, that it would be a 1-year project.
He wanted to get back to writing his 7-volume encyclopedia of programming!