Ex-colleague is holding grudges against me, is this a minor nuisance or is there something to be concerned of?
I used to have an ex-colleague (I’m in 20s and he’s in late 30s) and I was his assigned trainer.
Our working relationship started okay-ish, but turned sour because I was inexperienced at managing people, he struggled to adapt, I did not like him chatting too much on non-work/personal/gossip stuff at work, he did not like my way of pushing him during training.
I did not like that he kept making repeated mistakes and claimed he wasn’t being taught despite already being given the materials. I also did not like that he failed to make progress after I repeatedly bailed him out.
He did not like that I kept giving him work assignments and kept pushing him to practice tasks that he didn’t like.
He was more reliant on being spoonfed, while I practiced facilitated learning. We weren’t able to reach a common ground.
Also, he crossed my line, a few times. He didn’t like my way of teaching and wanted another colleague to be his trainer (that colleague was the only person in the office that entertained him), but instead of telling me directly or raising it to our line manager, he took MC from work, asked that colleague out, and asked that colleague to be his trainer.
Eventually, he quit in order to avoid being fired for failing his probation. By this time, nobody in the office talked to him because the entire team was tired of repeatedly bailing him for his mistakes.
I later learned that he had rejoined his previous company (he quit that company to join us because he said his company was too toxic). But here comes the weird thing:
Every now and then, he kept texting my colleagues, sometimes he shared life quotes, sometimes he sent video about workplace harassment, sometimes he asked other colleagues if they have contacts in their previous employers that they can refer him to, and sometimes he complained about being mistreated here.
More recently, he texted another colleague and reminisced his days in our company (he has already quit for almost a year now). He emphasised that I didn’t know how to teach, I had sabotaged him, and he would have stayed if another colleague was his trainer instead.
I find it odd that someone could hold a grudge for this long. Do you guys think it is just a anedoctal amusement, minor nuisance or there should be a cause of concern for me?