It's not about breaking yourself down to keep up with social demands from friends....because at the end of the day, if it's in your nature to be with and around friends even after a full day of work without the thought that it's daunting or something to dread, then that's who you are at core. If, on the other end it's something that's forced, or that feels forced, you have to think about if you're doing this for you, or if you're appeasing someone else's desire for what they think you should do. Understand what your needs are, and what the needs of people in your life are. Don't be afraid to articulate what you desire emotionally, and what you can or CANNOT do emotionally with friends.