I think as far as content goes, it's important to be able to distinguish between a genuine bid for connection and intimacy, and someone just wanting to discuss something they find interesting. They're sometimes different things. If my DH has a hobby he's passionate about and bores me, he can just as easily talk to people on an internet forum or a mate down the pub about it, and if that's what he's looking for, there's no relationship implication.
However, if your partner is actually, underneath the content, looking to connect with you, and says something about his day or his hobby that you can't really relate to, the only important thing is that you try generously to acknowledge and respect the bid. Even saying, 'I'm knackered now, love, but I'm really glad that came together for you,' with a hand squeeze, before going and having a bath is doing that.
It doesn't need to be a full on conversation. There's a way of being kind and respectful and closing down the interaction. That's not actually turning away. Turning away would be sighing passive-aggressively and saying, 'You know this bores me to tears and you've never properly explained it. But go on, explain it to me and I'll just sit here and nod.' Even though this extends the content of the conversation, it's deliberately shutting down the intimacy and kindness and humiliating the person for making the bid. That's the difference.