how does it explain why bad things happen? If it explains the good, surely it does the bad?
I'm not sure if it does have to explain why bad things happen?
It's more than likely a placebo effect and that's why it can work.
If you genuinely believe nothing good will ever happen to you, why would you even bother trying to make something good happen?
If you are convinced you won't get that promotion then why would you bother applying?
And then the flipside, if you genuinely believe good things will happen to you, with utter conviction, you'll be subconsciously more open to opportunities.
If you believe you are destined for that promotion then of course you are going to apply for it, which substantially increases your chances over the person who didn't believe and never applied. By spending a lot of time visualising how well you'll do at the job, you will probably find it easier to come across better in the interview, you'll probably be more confident and seem more determined.
It's not really woo or magic at all. It's just doing what you can to make the roll of the dice aspect of "luck" fall in your favour.
I completely believe in "law of attraction" type stuff and it's definitely helped me. If that's naive then why does it matter if I'm happy 😂