Asking because this happens to me a lot when I'm out walking my dog.
People stop and talk to me mostly about her (my dog)
But I never no what to say lol 
My brain temporarily shuts down and I'm left feeling like I've just been hit in the face 
♀️ 
Usually I go "Yeah she's nice int she" and then pretend to call my mum and leave lol 
Same thing happens if I go in the shops for butter and milk for mum and dad. Cashier always talks which is polite I guess but it awkward for me.
Everything I answer is one word like "yes" but each answer lol
I've never once looked at a random person and thought I'm gonna stop and talk to her lol