Let's take these in order, including our somewhat tongue-in-cheek headline.
As to the movement of persons, the budget, and the court - we wonder, does the EU's newly minted trade agreement with Canada have requirements in any of these areas? The agreement is the Comprehensive Economic and Trade Agreement or CETA, and our guess - we confess we are not sure - but our guess is that it does not impose new requirements on Canada in any of those areas. If that is correct, one has to ask: Does the EU really seek a trade arrangement with the UK that is less favorable to all parties than their agreements with third countries like Canada?
As for taxes, all countries compete with one another, whether they are inside a common group like the European Union or not. They compete for markets and they compete to attract investment, and in the latter competition, tax rates are a key metric. It is certainly understandable why one competitor would want to keep another from making itself relatively more attractive to investors with lower taxes, but it would seem strange indeed for a country seeking greater independence to tie its own hands on tax policy in the process.
Finally, as to shouting with the largest, it's from an episode in Charles Dickens'
The Pickwick Papers. Mr. Pickwick and his friends find themselves in a crowded, politically animated street scene, that gives rise to this exchange:
"Slumkey forever!" roared the honest and independent. ...
"Who is Slumkey?" whispered Mr. Tupman.
"I don't know," replied Mr. Pickwick, in the same tone. "Hush don't ask any questions. It's always best on these occasions to do what the mob do."
"But suppose there are two mobs," suggested Mr. Snodgras.
"Shout with the largest," replied Mr. Pickwick.