The last organ of the body to stop growing is typically the brain. Brain growth continues throughout childhood and adolescence, with the majority of brain development occurring during these early years. The brain reaches its full adult size in early adulthood, usually in the mid-20s, but some minor growth and changes can continue to occur throughout life. While the physical size of the brain stabilizes, neural connections, synaptic pruning, and ongoing learning and adaptation can contribute to changes in brain structure and function even in adulthood.