Usually, I mean it as:
This is something that's not independently verifiable but it has happened to me more than once. I can't prove it but I have direct experiential evidence that it exists.Examples include me talking to Eris or my seeing things with an inner light
I sometimes mean it as:
Some promise of something in the future with no proof available or possible.I don't use this meaning often and I try to be polite when I do use it this way but I don't always succeed. I suspect that this is the more connotational of the two.
In other news, somehow I have an earworm of "Puff the Magic Dragon" going through my head and I have no idea how it got there...