Sometimes I would go as far as to appear interested in what people had to say, and then take out my notebook and write things in a non-existent and incomprehensible alphabet, and show it to them, and then appear frustrated and angry at my poor condition of non-intelligibility.
Say “no” to everything. People who are mature are also very hard to get ahold of. Being a grown up is a full-time job and you don’t have the time to just hang out with your friends on a Sunday afternoon and have the time of your life. You’re busy being busy.