On climbs and their (relative) steepness

Regarding this post about a steepish climb in my near future, the following conversation took place.

Fearless Leader Joe:

You can handle that. It looks vertical on a map, but for 20m I bet that horrible one in Devon was worse – the one that I said as we were freewheeling down, “thank goodness we’re not going up this one”, to which you replied “Wait!”, and then we went up it on the other side.

Guy Jean:

Did we really only have that conversation once?

I do wonder if that’s the part he’s talking about, although that’s only 9% for a rise of 90m. There were definitely some shorter climbs that were steeper …