I figured going from C# to Java would be easier than C# to C++.
It is. Just jump in. I don't think [mike] is a full time Java coder either though you wouldn't know it.
Think of Java as C# without all the nifty stuff. When approaching a problem figure out how you'd do it without lambdas, function pointers, events, properties, valued enums, value type strings, etc. You just have objects and functions.
Then remember never to test string equality with ==, always .equals().
Now you know Java. Get cracking!