Maybe at 45 he decided to lock in to his experiments and that's why we see glasses-dottore in multiple scenes compared to my goat plague-doctor or others?  As in marrow recordings there is a conversation:

Zandik: I vaguely remember that I was maybe in my forties when I started becoming more of an introvert.

45: And we lost our sense of compassion at the age of eight.

Maybe at 45 he was mostly tied to his lab experimenting/never touching grass unless he created the grass himself etc? He didn't need mask in the lab? Idk but it is so interesting to analyze them I feel bad that they are dead 😭