Subdividing the Lima Bean
As a child, I was an extremely picky eater. My poor mother tried to get me to eat at least some of my vegetables, but I was a hard case.
For my own part, it was not a matter of will, exactly. I really couldn't bring myself to do it. Attempts to eat them would literally bring on a gag reflex.
Eventually the conflict would be pared down to an essentially symbolic level: "well, if you eat three lima beans, you can leave the table."
Unable to bear the thought of choking down a whole lima bean at once, I would then slice each oof my three beans into half a dozen minute slivers, and choke down each one by one with much wincing and shuddering, thus taking the work of thirty seconds and turning it into several drawn-out agonizing minutes.
"Subdividing the lima bean," thus, refers to that approach to attacking an unpleasant or difficult task, wherein the most painful part is drawn out needlessly.