person A: I had been expecting my friend to pick m e up for a shopping trip yesterday. Unfortunatley my friend never actually showed up.
person B: Sorry to hear that. Were they busy or did they forget?
person A: She claims to have had something unexpectdly come up. I think she just forgot. She often spaces out.
person B: You should not rely on her next  time. She seems unreliable! 
person A: That's probably a good idea. I keep forgetting though.