In Kuromukuro, Yukina’s mother forgets about her phone which ends up being the catalyst for the entire anime.
I did something similar once. I used to own one of those dinky push-up cell phones that exposed a keyboard. I barely ever used it since I rarely reached out to anybody of my own volition, and it had no capacity for apps let alone the Internet.
One day, I plugged it into the charger I kept in my bathroom (for whatever reason), and, in my infinite wisdom, I left it there – for three whole days. When I finally remembered to get it, I had more messages in my inbox than I had ever seen. Texts of the “Where are you?” variety from my cousins, siblings, and grandmother, and multiple missed calls from my parents wondering why I wasn’t picking up.
I later learned that my mother was ready to phone both my apartment complex and even the police to make sure I was safe since I was responding to literally nobody who contacted me. I apologized for my stupidity, and I promised never to do something so careless with my phone ever again.
Kuromukuro doesn’t get to make any more promises since it has officially finished, but its mistakes were more and grander than mine ever was.