Rediscovering the theory of identifiability: When I was in the first year of my PhD in statistics I came across an interesting problem that I thought would be a wonderful PhD topic and I spent many months solving it and writing up an academic paper for a journal. I was extremely happy with my paper and thought it would be a big deal, since it seemed to me that I had developed an important concept that would be a great addition to statistics. A couple of weeks later I got a desk rejection from the journal, and the editor was kind enough to gently inform me that while my paper looked very interesting, and was well written, my ideas "look a lot like the theory of identifiability" (a term I had not heard of at that time). Using this new term I did another quick literature search and discovered a huge literature; my own paper had essentially rediscovered an important mathematical/statistical concept that was already developed and published in about the 1950s-1960s. I had managed to get through my undergraduate degree without hearing this term, and so it hashad not shown up in my initial literature search, and my supervisors also did not alert me to it when I showed them what I was working on. So, I have the "distinction" of being one of the discoverers of the theory of identifiability (never published), which I discovered a mere sixtyabout fifty years after its original publication! It was depressing at the time because I had done a lot of work on it, but now I look back and laugh about it.