The phrase often implies feeling anxious or embarrassed in a situation that's not familiar. At the fancy gala, he felt out of his element and very self-conscious.
Pro Tip 2/3
Temporary Feeling
It suggests the discomfort is not permanent, but linked to a specific situation or environment. During her first week abroad, she was out of her element, but soon acclimated.
Pro Tip 3/3
Change and Growth
Being out of your element can be an opportunity for personal growth and learning. He was out of his element in the new country, yet it taught him so much.