A genealogist.
Researching my own family history has been absolutely fascinating, but I found it equally fascinating when for inheritance purposes I had to trace that of a more distant relative.
The picture that builds up, and the stories that you uncover are fascinating. I loved every bit of it, and found that as an activity it really suited my stubborn personality (like a dog with a bone if i think there is even the slightest chance of finding what I am looking for).
Mind you, for the second of those searches I had a lot of invaluable help from a fellow Gransnetter, who I can't thank enough. I won't say who she was/is, but if she reads this i would like her to know just how much I appreciated her help.
In fact, if I imagine myself as being a genealogist, I would also like to imagine her as being my supervisor/manager / mentor 😃