No guru or mentor can make you succeed with their advices alone . It is you who need to find a way to attain success for your startup.
If you keep knocking on the door of the best Guru or the most successful entrepreneur to get an idea validated before you begin your journey, It is not bound to get you any extra success .
He may be great man but genius is nothing but the art of following something you believe in .
He may not be seeing what you are seeing through your eyes. So don't waste your time asking feedback about your business plan or review your financials.
If your heart says it will work go ahead and prove it.
By starting either you win or learn some thing new for sure you will never lose.