Is this by any chance referring to mentally preparing himself for chemo or surgery or something like that? If so, i can definitely understand an SEI being concerned about pursuing treatment. He may feel fine in the present moment, and does not know if he wants to ruin his present feeling of wellbeing for a lower quality of life that (temporarily) comes with a treatment like that.
Actually it could apply to anyone, not just SEIs. It's a common sentiment patients have.