The title of this song alludes to Thom Yorke wishing he wasn't so sensitive.
According to Q magazine April 2008, the whoosing sound effects and ghostly whale-song howls were improvised by guitarists Jonny Greenwood and Ed O'Brien. They were only added at the Manor studios, 5 months after recording had started.
If counterpoint and polyrhythms are your thing, you might love these guys. Even by Progressive Rock standards, they were one of the most intricate bands of the '70s. Then their lead singer gave us Bon Jovi.