Govinda suspects that Siddhartha has found his own way to Nirvana without following a formal doctrine. Is this true, or has Siddhartha followed a pre-described path towards his goal?

I think Siddhartha is a bit of a rebel in that he strays from a pre-described path to find truth and enlightenment. I think this is a motif that comes up in the narrative. A person seeking truth and enlightenment must eventually do it himself. They have to explore themselves: nobody can give nirvana to them.