The thing about Peter Green is that he was endlessly humble about his bilities. He did not really think that he was a good songwriter or guitarist. Before Mayall, he largely played bass but switchted to guitar. He totally underrated himself. He'd even said that much of what he played was trying to find the right notes and oftren he thought is playing was embarrasing.
If only we could all play that embarrassingly!
It's good to know that even one of the greats felt like he didn't measure up. Not this should be dejecting but that we all understand that the road of a guitar player is continual learning.