Lennon had written I'm So Tired about his personal experience in Rishikesh, India, where too many hours of meditation coupled with his new fixation on Yoko Ono and growing alienation from his wife Cynthia (though she was actually with him at the ashram) resulted in many sleepless nights. John presented the song to the other Beatles when they recorded a batch of demos at George Harrison's house in Esher in May of 1968.
It was not until October, however, when work on most of the "White Album" had already been done, that the group finally turned their attention to the song. They spent much of an overnight session spanning October 8th and 9th starting, perfecting and completing the track before moving on to The Continuing Story of Bungalow Bill, quickly finishing that song off, as well.
They ran through 14 takes of the number on their usual instruments, with John singing his lead vocal live on every take. In addition to the Esher demo, the 50th anniversary edition of the "White Album" gives us take 7 and the basic track of the master, take 14. Add to that the Anthology 2 amalgam of takes 3, 6 and 9, and you have a fairly comprehensive overview of how the song developed at that session. Surprisingly, apart from George simplifying his lead guitar part, very little changed. John merely got more confident in his lead vocal and eventually got the best take that he was seeking.
Several overdubs were added to take 14 including a "far-off" guitar part played by George, three-part harmonies by John, Paul and George at the end of the first verse, and mumbling by John at various quiet moments throughout the track. All of these were omitted at the mixing stage except for John's mumbling at the very end of the song. An organ part played by John and some harmony vocals by Paul did make the cut.
John was always highly critical of the recordings made by the Beatles when he reflected on them in later years, but he was particularly happy with this track, right down to his own vocal performance. "I just like the sound of it, and I sing it well," he said.