I agree with your line of thinking TauPhi, but Cicero does seem supported by others in his representation:
Plutarch, Non Posse, 1099D:
"Not even one of us would believe Epíkouros that – while dying amid the greatest pains and illnesses – he was counterbalancing with the memory of pleasures formerly fully enjoyed. Someone would more likely perceive the representation of his appearance in the [ocean's] disturbed depth and surge than a memory of pleasure smiling gently amid such throbbing and bodily torment!"
We also have Seneca, Letters to Lucilius, 92.25:
"Does it not seem equally unbelievable that someone placed in the greatest torments should say 'I am blessed'? and yet this statement was heard in the very workshop of pleasure 'most blessed' Epíkouros said 'is this indeed: this day I am living' – even while on one side difficulty of urination was tormenting him, and on the other side the incurable pain of an ulcerated stomach."
And (although I shared this recently) Marcus Aurelius , Meditations, 9.41, quoting Epíkouros: "In my illness, my conversations were not about the feelings of my little body ¬ nor was I chatting about such things to those who visited but, while studying nature, I continued with the prior topics, even while in that very state, [studying] how the mind – although participating in such movements [occurring] within my little bit of flesh – remains untroubled, while preserving its own good."