I remember how with group, the last session for someone who'd decided to leave, they would open up more than they had the whole time they'd been in group :-) Could be you opened up because of your depressed feelings of "might as well, nothing else left".

New members always made me feel like I belonged more to the group since I'd be an "old timer". Remember your first week? There was a guy in my group who looked a whole lot like one of my brothers and had the same mannerisms and "expressions". All he said to me my first week was, "So, you're the new kid on the block?!" and I felt so welcomed and at home :-) We became good friends and also kind of dated and when I took him to my parents' house my parents and stepsister and nieces and nephews instantly pointed out to me how he looked like my brother :-) which was a nice confirmation for me.