Focusing, goal-setting, visualising and affirming definitely make a difference to where your life goes. The reason this knowledge has been a 'secret' for centuries is because the science didn't exist until relatively recently to explain why.
Reality is hugely subjective. The reason is the brain filters most of the stuff that hits you each day, including ideas and opportunities, it's partly to do with the RAS and partly the subconscious. If you feed the subconscious and RAS new ideas through visualising and affirming or whatever else it takes to change the way you perceive the world around you, your mental eyes will literally start to open.
Think about the woman in red in the New York crowd scene from the movie The Matrix. Imagine she's a new idea or solution to a problem. If she were dressed in a black business suit you wouldn't see her. The job of the RAS and subconscious is to dress the information you need in a red dress, so it catches your mental eye.
I am convinced that everything we need is around us, we just need the eyes to see it. But it's not a mystical concept at all. However, the mystical paradigm can help people with a certain mental model of the world absorb this shit and make it work for them.
The problem is the wankers who exploit people who are genuinely seeking help and advice on how to go forward. Salty Droid has done some great write-ups on people from The Secret such as
Joe Vitale and
James Arthur 'Death' Ray I got a lot from the teaching of Tony Robbins back in the 1990s but the guy seems to have lost it somewhere and become just another
money sucking another cult leader.
Coffee over ... back to work.