Lilly: you're not returning my calls again
Lilly: please let me know if everything is okay
Michelle: everything is fine, don't worry
Michelle: I told you that I will be on a training course this week
Michelle: can't really talk on the phone while in here, I'll call you after it ends
Lilly: oh, completely forgot about that, sorry
Lilly was worried about Michelle, because Michelle was not returning her calls. Lilly forgot that Michelle is on a training course this week. She will call Lilly after it ends. 