Antonyms for causing ennui include activities or experiences that are engaging, exciting, and stimulating. Some examples of these antonyms could be action-packed sports events or adventures, challenging games, intellectual pursuits such as reading and writing, creative endeavors such as art and music, socializing and meeting new people, or exploring new places and cultures. Anything that captures attention, stimulates the mind and senses, or offers novelty and surprises can serve as an effective antidote to boredom and ennui. It is essential to incorporate these kinds of activities into one's life to maintain a healthy and vibrant mind and spirit.