Data that bundles together, is learned together

It was the winter 1998 and I have just moved to Baltimore from Italy. Ernst Niebur at the Mind Brain Institute, Johns Hopkins University. At the time I was fascinated by the neuroscience of vision, and was trying to learn from neuroscience book how the brain works, how it makes sense of the stream of sensory information. One concept that was absolutely nebulous was how a brain would "learn", or connect the sensory stream data to actionable insights. "Hebbian learning" kept coming up -- a learning theory in neuroscience stating that "neurons that fire together, wire together".