I mainly talk about:
ASD, some personality disorders I've been researching (mainly antisocial), the things I make (DIY stuff), cats!!, videogames.
I can generally talk to anyone around me and listen to them, unless l dislike them. Most of the times, I clearly remember what they say to me. I avoid long conversations, unless someone is saying something important. Lately, I've talking a lot about Aspergers (or level 1 ASD). Two people are concerned I'm obssesed with the topic, lol. Also, I can feel "tired of talking to people" and need my time alone.
I'm really happy so many people here like to talk about cats!