Wonderful narrative - thank you for writing this. It's close enough to my experience to ring many bells, but different enough that it was excellent to read.

I did Part III in '83/84 and a PhD in DPMMS from '84 to '87, and having come in to the Cambridge system from outside, I was way out of my depth. The amount I learned was quite unbelievable.

If you'd like to connect and share experiences, by contact details are in my profile.