Much as I love to pile on the Conservatives, he isn't really bragging that he swam in raw sewage or saying "it did me no harm", he's saying that it's not a new problem in the UK.

What I would criticise him on is that a) the dream of the ratchet of progress making things better and better for future generations isn't working, b) it's backsliding, c) it's backsliding under his government's governance.