Lex de Boer, a 77-year-old from Avenhorn, Netherlands, has completed a marathon for every date of the year, achieving this milestone with his 758th marathon. The final date, December 1, was celebrated with a surprise from family at the finish line. De Boer, now aiming for a total of 777 marathons, reflects on his journey that began with 700 marathons two years ago and highlights the support he received to cover the missing dates.