Why Hieronymus Bosch is considered enigmatic?

Answer 1

One of the most fascinating of the Netherlandish painters to viewers today (1450-1516), whose work depicts a world of fantastic imagination more often associated with medieval than Renaissance art. A superb colorist and technical virtuoso, Bosch spent his career in the town whose name he adopted, 's-Hertogenbosch. Bosch's religious devotion is certain, and his range of subjects shows that he was well educated. One of his most famous works of art: GARDEN OF EARTHLY DELIGHTS; A triptych, oil on wood panel, center panel 7'2.5" X 6'4.75'' (2.20 X 1.95 m), each wing 7'2.5" X 3'2" (2.20 X 0.97 m)

Art History Volume Two by Marilyn Stokstad. Page 729