well he can't win them all
you know I also read a lot of Fedfans who say "oh if Fed had won those points there why is he so bad mentally not to finish that set against Djokovic" ... not even seeing that actually Djokovic had accelerated in those moments and played a level which Fed couldn't reach in those matches.
With ifs ... (and for instance Fed has not been as ruthless in tiebreaks as he was usually : won only 59% of them when he was rather at a huge 70% previous years ... and THAT was again the fact in that WTF final)
This year Djokovic lost crucial sets 7-5 to Murray and Nadal ... but he also won some (notably in Melbourne)
He lost two ones to Tsonga in Roland-Garros but still won the match.
That's exactly what I meant, he wins some he loses some so I don't think his mental toughness is not what people made it out to be.