Absolutely. A few weeks ago a bunch of us were trying to remember who recorded the 80s song, "True". We thought for hours (with no Internet handy to consult) and never did think of it. Last weekend the same gang was together again, and someone asked if anyone had figured out who sang "that song". At first I couldn't remember what the song had been, but as soon as someone said "True", I said, "Oh, that was Spandau Ballet." I hadn't thought of it for a second in the intervening time, but because I wasn't searching for it, the answer popped up with no problem.

Oh, and Bel, "chortle" and "galumph" are probably the most well-known examples of the "Jabberwords".