Blood levels of proteins reflect the starting, stopping, and changing of biological processes linked to aging. We make significant changes at three ages. — “The wiser mind mourns less for what age takes away than what it leaves behind.” This is the insightful observation of William Wordsworth (1770–1850), the English romantic who (along with Samuel Taylor Coleridge) helped initiate the Romantic Age in English literature. Together, they published Lyrical Ballads in 1798.