Training is indeed happiness (at least it should be). But imagine one teacher is teaching you to move one way and another teacher is telling you to move another. In both teachers classes, you inevitably confuse the two ways of moving. I can understand that it is still training and that training may still be happiness (regardless of conflicting instructions slowing it down) but that is the "problem"(issue) being discussed.
Eh, just go with it. You'll find your own style some where in between.