Lol... Never. Ridiculous to me...
at the very least, it helps narrow down goals. we're more likely to make choices and do things that lead to reaching these goals if they're visible and freshly reminding us.
it's uncanny at times. I'll write something down and it'll just fall out of the sky. I don't question it, I do'nt depend on it. But it's interesting.
We only use 10% of our brains, and we barely understand a fraction of what makes people work, how they brain functions, etc. In 1000 years, people will be able to map and duplicate brains. But we cannot do it today. So whatever non-obvious powers of the mind that we have today... hey, might be something to it. Sourcing and vision board works for a lot of people.