Foolguy That was an interesting read, I find that over time I tend to mimic some habits of people in the group I'm in, but I'm not sure if it's part of the getting along process. What worked best for me was making individual friends, and being introduces to their circles. I got to know the group and got along as well, of note is that topics of discussions are often the same, sometimes even word for word. Rest is ranting about the news or small talk. It(s not my cup of tea but I enjoy it occasionally. I guess my point is to try doing mindless things once in a blue moon and you might make friends more easily. Comon ground is always just a conversation starter as you've noticed, rest is "vibe" as I've heard it, so wether or not both parties look interested, remember stuff, laugh together and that's pretty much it I think.
COUPLED You did well, get better soon!