Like I said, the above list is certainly not all inclusive. Actually, in a broader sense, horology is defined as the science of the study of measurement of time, although in a more common use I think answering yes to any of my above questions would qualify you as one.
Even a watch enthusiast could call themselves a horologist-there's no legally binding definition of this, and a "watch enthusiast"-I don't think-would be out of line calling themselves that. In a sense, I think it's a title you bestow on yourself, as you know the level of interest and knowledge you have.
But, at the same time, I'll also caution that a little bit of knowledge can be dangerous thing
I consider myself to be a serious Waltham collector and spend a lot of time research not just the watches but also the history of the company. BTW, as a side note, when researching an historic company that is no longer in business, research on the watches typically comes from factory records and observations(i.e. actually looking at the watches). Many new collectors get caught up factory records, but as a collecting friend of mine likes to say "the watches tell the story." Just because the records say it's supposed to be something you can't count on the watch actually being that. Just for example, I've spent a lot of time pouring over the Waltham factory ledgers, and have found one particular watch-sn 50,194-that has a very peculiar notation. I would
love to see this watch-it may no longer exist, it may be buried in a collection somewhere of a collector who either doesn't like to talk or doesn't realize its significance, or it may be "in the wild" still.
And, on that note, I think that's enough rambling from me for the day