Or, good reading habits make you smart. I know tons of people who don't take Iodine but are good readers, and they're really smart. The more you read and learn, the smarter you get , even without taking oodles of iodine. Taking Iodine alone is not what makes a person smart. Otherwise, we'd see people who take Iodine magically transitioning into becoming geniuses. It doesn't work that way, unfortunately, more effort is required on the part of the individual, this is well-known.
The little old car that is your body or brain can chug along only so fast. Maybe iodine turns your 4 cylinder engine into a supercharged V8.
But without good habits, it doesnt matter.
The tortoise and the rabbit parable comes to mind, that slow and steady wins the race. A person who doesn't take extra iodine but is steady in their efforts at whatever goal they have chosen, can blow away a person who takes iodine but doesn't have any goals.
Putting a monkey behind a V8 is not as good as a human with a one-cylinder go-gart, who persistently chugs along.
Iodine does not create geniuses, it only perhaps makes a person more inquisitive and oils up the mind to perform better. But taking iodine doesn't make a person a multiple PhD, or an MD. It only gives capacity perhaps to do more work. The rest is up to the person as to how they drive their improved vehicle.
Those with mis-guided habits or lacking a desire to get off their duffs in the first place, iodine won't necessarily help.
Maybe, it only makes a person better at what they inherently are, and if they were inherently lazy, it only makes them to be better at being lazy !! etc.