The quote emphasizes that merely considering the absolute size of a brain does not provide a complete understanding of its capabilities. Instead, the relative size of a brain in relation to an organism's body size is a more significant factor in determining intelligence and cognitive abilities. This perspective highlights a common oversight in assessing the complexity of brain functions.

In his book "A Short History of Nearly Everything," Bill Bryson sheds light on how misconceptions can arise from focusing on absolute measurements rather than context. This insight encourages a more nuanced view of biological evolution and intelligence across different species, stressing the importance of relative comparisons in understanding the intricacies of life.