One time I was working on the Budweiser account, and we spent a day getting a tour of the brewery. I learned that Budweiser is made with 30% rice. I learned that the brewmasters crushed up the glass that the pipes in the brewery were made from, turned that into a tea, and drank it, to check it was taste-neutral.

So it was quite an interesting day. But, useless from an advertising point of view. Because I've never seen a beer ad that was based on specialist knowledge as to how a beer is made.

(Has there even been one, N.B. that relied on real specialist knowledge? I have heard about a campaign for Schlitz beer that claimed the bottles were "washed with live steam" - but that was in the early 1900's.)

We would have been better off spending that day thinking of ideas, rather than traipsing round a brewery in west London.

The agency where I've recently become the creative director has a car account, and they were pleased to have me on board because I've done a lot of car advertising over the years. But you know what? I actually have no idea how an internal combustion engine works.

And although I kind of hope my car client doesn't read this, I contend that it doesn't matter.

What matters is understanding what matters to people, and how to communicate that.

Here's my favourite ad from this year's Super Bowl. It's for a Hyundai that has a turbo engine. And I don't know if the creative team that made the ad have any understanding at all that a turbo engine works by a type of forced induction system, which compresses the air flowing into the engine. (Nor did I! I just googled it!)

But what they've understood brilliantly is the benefit to the ordinary driver of having a turbo engine - you won't get stuck behind the car in front - and how to communicate that in an engaging way (see ad below).

That's what matters.