I knew Preston quite well - he mentored me in the scholar program - but I never knew of his connection with Turing. When I did find out I started to make enquiries about re-establishing contact, but Preston now has advanced dementia and doesn't recognize even close family.
Such a lost opportunity, primarily because I was young, self-absorbed, ignorant, but believing I was clever and knowledgeable. And now the chance is gone forever. This is why I now try to take every opportunity to connect with people who have stories to tell, and encourage them to talk.