Neuroplasticity is a correction of a genuine scientific error, not a discovery, as for most of the 19th and 20th centuries, neuroscience assumed the adult brain was a finished product. 1906 Nobel laureate Santiago Ramón y Cajal declared that “In adult centers the nerve paths are something fixed, ended, immutable,” a tenet repeated in textbooks and practiced by clinicians until the 1990s. Research from the 1960s onward demonstrates that the adult brain remodels itself continuously, with new neurons generating throughout life in the hippocampus. However, the article notes that “rewiring” is an inaccurate engineering metaphor, as there are no wires in the brain; what changes are electrochemical thresholds, synaptic efficiencies, and receptor protein density. The word “neuroplasticity” migrated from the laboratory to pop culture in the early 2000s, where its meaning changed from a specific set of measurable synaptic mechanisms to a concept of putative empowerment in self-help and yoga studios.