what does Smiley mean when he says..
In the first episode he says 'I can give my own damn reasons, and that is not the same as the half baked tolerance that comes from not caring'?
This statement was made when Smiley was riding in Peter Guillam's car down to see Lacon at his home in what is described as "Drakula's Bloodband," in the countryside. Smiley had endured half an hour of hell at Roddy Martindale's club being quizzed about his service under Control, what his present activities miight be and sneeringly reminded of Ann, his wife's lack of faithfulness to him as a spouse. By and large George Smiley was feeling pretty low and angry as he trudged home "along innocent pavements."
The statement 'I can give my own damn reasons, and that is not the same as the half baked tolerance that comes from not caring' means that he can still justify himself as a worthwhile operative within the Circus, as the remainder of the story goes on to show. Smiley's ability to work towards the entrapment of Karla is only just beginning and is finally brought to its conclusion in Smiley's People
Such is my interpretation of this somewhat bitter remark. He has reached a low point in his long career, but is not prepared to give way to what Roddy Martindale and the Circus might think of him after he had been sacked.