The theory is that hiccuping is a remnant from an ancient stage of evolution. Namely, the moment where our great-great-great-great-ancestors under the sea took a look at the giant hellbeasts their aquatic living environment was riddled with and turned their gaze to the relatively horror-free land environment. The first obstacle they had to overcome was the whole issue with breathing. After a few attempts, they realized that they obviously couldn’t just jump on land and go “ta-da!” So they adapted by small steps. As evolution started to toy with the concept of “lungs,” these creatures weren’t ready to fully commit to breathing air and kept their gills, remaining amphibious.
Eventually, the gills went away – but a small remnant of the system that operated them remains inside you even today, and every once in a while it goes “Oh shit, I can’t breathe!” and gasps for air for a while before it remembers that it technically doesn’t exist.
So the next time you get a nasty case of hiccups, cherish your ancestry – it’s just this guy waving from the annals of history.
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