You know, the process of making a documentary is one of discovery, and like writing a story, you follow a lead and that leads you to something else and then by the time you finish, the story is nothing like you expected. ↗
The thing that people associate with expertise, authoritativeness, kind of with a capital 'A,' don't correlate very well with who's actually good at making predictions. ↗
To the extent that you can find ways where you're making predictions, there's no substitute for testing yourself on real-world situations that you don't know the answer to in advance. ↗