From Longman Dictionary of Contemporary Englishbe in your elementbe in your elementENJOY/LIKE DOING somethingto be in a situation that you enjoy, because you are good at it Graham was in his element, building a fire and cooking the steaks. → element
Examples from the Corpus
be in your element• All in all, he was in his element.• Now he is in his element.• He smiled at the ease of it; one minute the fish was dying, the next it was in its element.• The ravens are in their element.• While the fighting took place in open country, the Legionnaires and Regulares were in their element.• On the soccer field is where Christina really feels like she is in her element.• They are in their element, and they want to stay.• Wetland plants will be in their element, so long as they are given generous mulches to keep the moisture in.• She would be in her element. 