I was at school with a girl who was really nasty horrible bully. She was quiet and not popular and very much under the radar but she horrifically bullied several people in my year group, including one very good friend of mine for several years. I also bore some of her nastiness but not to the same extent. She was/is just a very unpleasant person and I'm sure deep down was deeply unhappy. She has never changed as I know various people who still know her but I have had pretty much nothing to do with her since leaving school.
5 years ago she unexpectedly joined my work place and sent me a private message on social media being very friendly and asking if we'd like to meet up. I ignored it although I screenshot the message. A few weeks later, I saw she deleted it.
She has randomly popped back up again in my life through an extended acquaintance and it's got me thinking again about why she deleted that message. I've always wondered and thought it was quite a strange thing to do.