Mental self-care includes doing things that keep your mind sharp, like puzzles, or learning about a subject that fascinates you. You might find reading books, listening to audio, or watching movies that inspire you, fuels your mind. If it involves thinking or learning, it fits into the mental self-care category. While this sounds like a set of activities purely aimed at introverts, it might also include group or social tasks like escape rooms, or trivia nights, which might appeal to extroverts as well. Remember though, it is an activity you do for recharging and enjoyment, not as part of a required task [like research or study for a work task].