How can this exam be "difficult"?

I've been reviewing and making my study guides and the more I review the more I'm getting paranoid. I know this is an intro exam but either this exam is perfect for me at the moment or I'm not picking up where Sun could make this exam tricky/difficult.

Does anyone notice any parts of the objectives where the questions may pick some minutia to trick or cause testers to stumble? Small details? Aspects that should be high-level but can't tell where high-level ends and low-level begins?