That's what I meant by "the sheer fun of it". I would never say that people don't enjoy riding in fast pace lines. I'd probably enjoy it myself, and the few times I have joined in, it's been exhilarating. But if it's not specifically your thing, then there's no particular urgency to train yourself for a paceline, or to even learn how. It's not one of those must-have cyclist skills unless you're racing or want to ride with people who ride in pacelines. It doesn't generalize to much of anything else in cycling.