Berts bekymmer (Swedish: Bert 's worries) is a diary novel, written by Anders Jacobsson and Sören Olsson and originally published in 1994. It tells the story of Bert Ljung during the calendar year he turns 15 during the autumn term in the 9th grade at school in Sweden. The book only uses chapter titles, but no names. The book also introduces a new concept, "Dagens dikt" ("Poem of the day"), a poem connected to the chapter plot.