The secret factor that decides if you'll succeed this time or not

A couple of months ago I took 2 clients at the same time, starting the same type of business. It was fun because I would do similar work with them at approximatively the same time. Then of course everyone is different and the pace and topics went more and more apart. After 7 weeks one of them landed her first big client. !# weeks later she is still going string and added a few more wins to her business and bottom line.
The other client has not landed any client yet and is still posting her offer on social media waiting for customers to call.
What do you think the crucial difference is? They both were exposed to the same business skill learning process, given the same access to materials and advice and both spent many hours building their craft.
It turns out that business skills are the easiest part to learn. The real obstacle proved to be the mental obstacles. Whereas my first client was willing to open up and challenge her inner beliefs and mental blocks about self worth and money, my second one invested an impressive amount of time in activities meant to keep her away from the realization that her first project is in the inner self area. At the end of the first 13 weeks she arrived at the conclusion that it is finally time to face the truth and understand what holds her back.
I am happy for both of them. I think we all are here to learn how to be happy and having our own business is a way for some to do just that. We will make money and we will find success and professional recognition but the best of this experience is us becoming our best selves in the process and the golden opportunity to face and bring back to balance parts of our being that would have been exposed should we have taken any other route in our professional life.
How important do you think mindset is in your success as a business owner?