[solardev]

Do you like physical activities (or can you learn to?) Rock climbing, mountain biking, martial arts, kayaking, etc. are all great for this, grounding you in the moment and making you focus.

Otherwise... I don't think this is a really great lifestyle suggestion overall, but maybe in your specific case, only for limited doses: Video games? There are many puzzle, card, and strategy games that require a lot of focus and thought. Or yes, chess. I don't mean reflex-based shooters, but more thoughtful, turn-based titles.