Surprised to read this quote here! This means nothing/no one can guarantee you being a psychoanalyst. Just like either you can code and be good at it or not. That's all this phrase means. Of course it gets tricky. A programmer can show the result and it either works or it doesn't. An analyst can't show anything, really. Even if the analysand claims his/her life has changed because of an analysis (people also claim Jesus changed them, for example).

About the floating attention thing, that's a very strange generalization ("analysts don't pay attention"). It is about treating all the "material" equally (ie without preconceptions).