I saw this speech by former Fed President Jerry Jordan and note he highlights the lack of accounting knowledge by economists as a big problem. I remember when he first made this point at a meeting circa 1988 when I was a worker bee in his economics department at a Los Angeles bank. He was excited that it seemed to make an impression on people he respected, and I could see he felt like he had identified something really cool: an insight new, true, and important.
Good speakers are good precisely because they practice a lot by giving the same speech in different venues, each to a different audience. Jay Leno, who I saw several times in the 1980's when he was on the comedy circuit, said in an interview that the difference between the tonight show and the comedy circuit was that in one you gave the same routine every night in different places, but on the Tonight Show you gave a different routine every night in the same place. That he practiced his delivery on a similar routine for a decade helped his timing.
Still, 25 years is a long time to be making the same modest point. It's a good point, but not earth shaking, sort of like the idea that the 95% Value-at-Risk dominates the 99% Value-at-Risk because it's actually feasible to validate, or that in banking its all about spread, credit quality, and volume, and you can't maximize all three (sort of like universal access, quality, and cost in health care), or never give a Sunday lecture at a four-day conference. I'm hoping my idea bag has more stuff so I'm not making these points in 25 years, but then again, he was a quasi-governmental leader so I'm sure he's used to repeating himself in front of big audiences.
I do find it is a useful rule of thumb to evaluate someone's intellect by how frequently they repeat themselves. If you remember them telling you the same three minute story that has some funny/surprising/shocking ending (it's their best story), you can be pretty sure their idea bag is empty.