I don't remember a time when the entire medical community thought marijuana had zero benefit. I remember them acknowledging that there were anecdotal accounts of it helping people, and being frustrated that research into it was strictly forbidden.
On the other hand, an open mind is good. I think most of us have one. But being too credulous isn't good. I've worked with a lot of people who smoke cannabis, it's pretty common in software development. None of them are great at remembering things.
Anecdotes are useful especially when there's zero data. But know they're limited in what they can tell you.
Don't believe a research study. Wait for ten studies.