I found that quite odd as well, but I mean if someone loves doing what they're doing and are bringing value to the table, why not? For many elderly people it might be better if they keep working on something, instead of losing all connection to reality just sitting at home.

I meant it's crazy impressive. Three of four grandparents I had lived quite long lives, and I witnessed first-person how their once exceptional mental capabilities quickly deteriorated once they've crossed 88-90 years threshold. Being able to still work regularly at that age is just an amazing achievement.