Rich Muno’s sculpture ‘‘Young at Heart’’ depicts Johnny Kelley crossing the finish line at age 27, when he won his first of two Boston Marathons, and at 84, when he ran his last Marathon. Kelley, who ran the Marathon 61 times, died last year at age 97. The statue is along Heartbreak Hill, a name said to have been coined in 1936 when Kelley ran neck and neck with Ellison “Tarzan” Brown. Kelley tapped Brown on the shoulder as he passed him. Brown then sped up, and Globe sports reporter Jerry Nason wrote that Brown regained the lead, “breaking Kelley’s heart.”