This week, Brent speaks with Sir Adrian Bird, the pioneering geneticist whose discoveries on DNA methylation reshaped our understanding of how genes are regulated. Bird explains what DNA methylation actually is and why he's skeptical of popular claims that it determines "biological age" or can be easily hacked to reverse aging. They discuss his groundbreaking work on Rett syndrome, how CRISPR gene editing is being used in clinical trials to potentially cure it, and what that might mean for other neurological diseases. He's a wonderful guest. Hope you enjoy.