Brexit. I could go on for ages about specifics, but experience says that nobody outside the UK really cares (it’s so 2016), and nobody inside the UK is changing their minds.
Ah! Partly the total incompetence of the people who are in charge of making Brexit happen, partly because I don’t trust the UK government with human rights unless bound by international convention (a bind which looks like it will be a lot weaker after Brexit).
It’s unfortunate, really, there’s a lot of nice stuff in the UK too. And I know I’ll miss it.