No, not right. But everyone's heading in the right direction. Here's the answer...
Picking up my phone in the dark, my fingers naturally fall across two buttons, one of which brings up the contact list and the other of which makes a call - and it calls the first person on the contact list which, because they're in alphabetical order, is Adam. Apparently I've done this several times over the last couple of months, always in the middle of the night.
Having been woken yet again by an accidental call from me in the small hours, Adam texted me Abena's number, knowing that she would go above him alphabetically in the contact list, and she'd get all future sleep-disturbing calls.
Brilliant, really, especially at half past four in the morning.

