Came across Cecil’s answer after I read a claim on TV Tropes that it was in reference to upper crust-mocking HMS Pinafore, and that the self-deprecating reference to it in Pirates of Penzance and its ending (the pirates surrender in Victoria’s name) were attempts to placate her.
It doesn’t make sense. The big butt of Pinafore’s humor is W. H. Smith, and the whole point of the joke was that he wasn’t upper-crust – just filthy rich. (Yes, it’s the same W. H. Smith.)
For significant quotes by Queen Victoria, I’d have thought “We are not interested in the possibilities of defeat; they do not exist” would rank before “I will be good”.