I like Lojban because of the difficulty of it. (= I like Lojban because of its difficulty.)
Etymology
Formed from rafsiloj (logji) and ban (bangu). The cmene form of this word (that is, ending in a consonant) is used specifically for the language itself, as opposed to the possible lujvolojbau (which refers to a logical type-of language, often--but not necessarily--Lojban).