“Dave, I can feel it.”
That answered the question posited HAL before the breakdown.
On the voyage, Dave asked him, “Do you think you can feel, HAL?” HAL responded that it did not know.
If you watch the movie without knowing what that sentence meant, you missed why this was such a hard decision for Dave Bowman. The only sentient being that he was likely to ever interact again with was being slowly degraded by his actions. The scene in the computer core is a defining one for the movie but the meaning behind it is lost to most, as is the final Star-Child apotheosis scene.
Bowman stranded himself, bereft of any companionship. I imagine Michael Collins (Apollo 11) might have felt a bit of compassion for this poor guy watching this.