Don't forget simple misunderstanding'
My bestie (20 years next year) ALWAYS answers the phone. I (with everyone else) ONLY answer the phone when I have time to talk.
Several years ago, no childcare, I almost never had time to talk. She 'sat me down' and laid down the law. She doesn't care if I can't talk, just say so.
Huh. Lightening strike.
She calls, I answer & say 'Sorry, can't talk right bye! Love you!'
Like your friend, at the time, I had MAYBE once a month where I could talk. She was FINE with that, as long as I answered.
We now talk once or twice a week mist weeks. Sometimes daily, sometimes monthly. Our schedules fluctuate quite a bit.
15 years (then), and you'd think we had phone etiquette down. Nope. In my mind it was rude to answer when I couldn't talk right then... And in hers rude to not answer.