I maxed out at 23 years of age at 145 kg (320 lb) for reps unspotted. Can't get close to that now though :D
I think that is because what muscles you train from childhood those are stronger and shorter arms create less leverage against you in bench press.
I think the shorter arms for me was part of it for sure. Half gorilla. I don't think bench press is a very good judge of strength, or at least, not quality strength. I am more interested in overall body function, especially since my body has been failing since I was 16. It would be nice to wake up painless sometimes.