He left in 1967, with six GCE O-levels and two A-levels in history and French, at grades B and C, respectively.
This brilliant scientist, with all of that private school tutoring, didn't get enough A-level qualifications for most UK universities by 1960's standards, and certainly not for Cambridge, where he got an Arts degree.
The Cambridge "Masters Degree" bit is described as “an academic rank, and not a postgraduate qualification.” and needed no more study.
He is not exactly a scientific mastermind...:^)
The House of Saxe Coburg and Gotha...er, Windsor doesn’t breed them for brains.
Inbreeding