At kindergarten, Martin was a bit different from the other 4-year-olds. When they counted to 100, he stopped at 4.
To play with his idea, he set up a space rich in symbolic material that he had already mastered. He obviously understood the way 4 can be manipulated because he was drawn to the visual tension between the three superimposed crosses of the Union flag. He instinctively chose repetitive humming of a (linked) theme with subtle 4-measure phrasing.
This is how we think. It could have been the play of thought in anyone of any age:
Martin reproduced existing symbolic spaces by painting and humming.
By rigorously co-opting these tangible representations from the social imagining, he held his space intact against the distractions around him.
Within that space he could observe anomalies, conceptualize his idea, then test its validity.