OK...that was highly confusing.
Let me see if I understand your argument:
1) You believe that, because he's already been caught with PEDs, he has to be more careful NOT to use them (because they'll test him more often), and the fact that he has not been caught again suggests he's clean now.
2) You believe that the real reason for his jump in performance is a renewed optimistic approach at the plate, and not the performance enhancers (didn't understand any of the comments on horse racing, but that's probably just because I don't understand horse racing...:) )
Do I have that right?
If so, I'm not sure I totally buy it. It is certainly possible that he is visualizing more positively and, therefore, getting better results. I know such things do occur. But There isn't much evidence that the Cruz from 2011 or 2010 was a cranky, unpleasant fellow who didn't enjoy playing. Other than, perhaps, his injuries. :)
It is a known correlation, BTW...guys who are very injury prone and then suddenly are not very injury prone later in life are the ones most likely to be busted for PED use. I believe it is likely that Cruz used for an extended period to shake off all of his injuries...and that it made him a much better hitter...and that being a much better hitter made him happier.