The only thing I did that wasn't healthy was play videogames and watch tv for many hours each day for my entire life up until I got pois.
I played sports at least once a week, had a pretty active job as well. Always thought that maybe i wasn't eating enough(have always been skinny).
I tried to remember what i did just before POIS and i do remember playing video games quite a bit, watching tv as well. Went to dentist for tooth pain(ended up on some antibotic). I had some stress during that time as well(but have for most of my life so nothing new). POIS definitely started shortly after.
BTW, could video games cause any permanent damage? I remember getting headaches frequently and really not wanting to stare at screens few months after that(and still minimize that today). Because of those i went and had a CT scan and they didn't find anything wrong. They said probably tension related.