How am I not myself?

I'm back in good old Marietta, GA, hanging out with my family and friends and trying to raise a little support (I accidentally left all my support stuff in Montevallo so we'll see what happens with that). Anyways, I've been hanging out with alot of my old friends and they keep asking me if I'm ok and saying things to the affect that I'm not acting like myself. That makes me feel weird. I went running this morning and I spent most of that time doing an internal psycho-analysis of myself, trying to figure out why I'm acting weird. This of course left me pretty mentally exhausted. Bottom line- life is changing, my friends are changing and I'm changing. Most of my friends here are married- so they talk about buying houses, having children, relating to their husbands, and what's going on in their social circles. I can't give much advice or input on those topics but I do enjoy listening and learning. When people ask me what's going on with me, I never know how much they really want to know so I keep it brief. My job and my life are probably seem as foreign to them as their world is to me. It's good for me to be here, I just need a little time to warm up.