I just hang around pretending I know something
If you're talking about walking around, waffling about would mean rambling. But rambling (going on and on) and waffling (going back and forth) when speaking are not usually the same. At least here in the US. It is always interesting to see how other English speaking countries have different uses of words.I thought waffling meant rambling (it does have rambling further down the page, I'll put that down to US vs Australian English), so I didn't get the joke either.
While I'm here, I'd love to hear some opinions on the Gravity Expansions.