Looking for a Discworld book a quote is from (and the full quote)

Question

I've been thinking about a quote from one of the Discworld books which went something like (from memory and not in the tone of Terry):

The thing about insurmountable mountains is that they are until they aren't. And then a generation after that old ladies will stroll up to its peak as an afternoon stroll.

What I took away from it was that things are really hard until someone does it the first time, and then it gets a lot easier since there's a way.

Anyone know which book this might be from? Or what the real quote was?

Answer 1

This is from Maskerade, in relation to Greebo the cat's transformation into a human.

The allusion is that it's very hard to do something once (e.g. turn a cat into a man) but that once it had happened, it was infinitely easier to accomplish again.

But magic is never as simple as people think. It has to obey certain universal laws. And one is that, no matter how hard a thing is to do, once it has been done it’ll become a whole lot easier and will therefore be done a lot. A huge mountain might be scaled by strong men only after many centuries of failed attempts, but a few decades later grandmothers will be strolling up it for tea and then wandering back afterward to see where they left their glasses.

_^Maskerade