Well, I began on C++, so I know what it's like. You just have to be able to understand the ideas of what a class is, and how it works. And when you should use one, and what you should use one for, and such. Because that stuff tends to come easily to me, learning classes, inheritance and such was easy. Of course, after learning C++, Java is a breeze, you just learn to HATE writing GUIs in it.
PS: I also have worked with VB, C#, Java, Some Perl and PHP, Turing, and I'm sure I'm forgetting something.