All words are cool if you don't know what they mean. If the reader knows what it means but the writer doesn't, the effects are less predictable and desirable.
I disagree. I don't know what "venial" means, but I don't think it sounds as cool as "penultimate" :-)
well not knowing what venial means is venial after all.
I'd upvote you, but then you'd know I was lying (which isn't as venial).
Penultimate has this in common with "literally". It's most often misused to mean the opposite of what's intended.
Cue Inigo Montoya.
I'm not entirely sure if "next-to-last" and "last" can be described as opposites, though :-)
Well, there is this: Opposites are a tricky concept, not well-defined in most domains. Your implication is that the opposite of last is "first". But doesn't it make at least as much sense to say the opposite of last is "not last"? From a programing/math standpoint, it seems like a strictly better, less arbitrary definition.