Lojban is not hard. If you have experience with formal language/predicate logic/programming it is trivial to modify that understanding.
How about having a conversation in it. (In normal conversations, people just don’t have the time to engage in Type 2 processes—most utterances take a few seconds at most. I’ve heard that lots of people tried to learn Lojban well enough to have real-time conversations in it and failed.) Also, the French, German, Russian, Spanish, or Portuguese you studied in high school are close enough to English—not only genetically (all Indoeuropean languages, FWIW), but also typologically—see http://en.wikipedia.org/wiki/Standard_Average_European. I’ve heard that native English speakers have an easier time learning French than Indonesian (probably the simplest non-creole natural language), FFS.
How about having a conversation in it. (In normal conversations, people just don’t have the time to engage in Type 2 processes—most utterances take a few seconds at most. I’ve heard that lots of people tried to learn Lojban well enough to have real-time conversations in it and failed.) Also, the French, German, Russian, Spanish, or Portuguese you studied in high school are close enough to English—not only genetically (all Indoeuropean languages, FWIW), but also typologically—see http://en.wikipedia.org/wiki/Standard_Average_European. I’ve heard that native English speakers have an easier time learning French than Indonesian (probably the simplest non-creole natural language), FFS.