The civil service will eat you alive - it just takes a few decades to digest you.
I bumped into a few "patriotic" types at a certain weather forecasting arm of the Civil Service, about 15 years ago. One guy there even ostracised me because I eventually quit for what was a ~50% raise to work for Sun Microsystems.
The irony he could never know was this: What prompted me to leave was a very bitter conversation I overheard in the kitchen: One guy had been a lifer in the organisation, and was lamenting what the return on his time had been, and how things could have been so much better if he'd put his own interests first. I remembered thinking to myself: "Good point!" - I was still in my twenties, then.
(To me, the scene in The Great Exotic Marigold Hotel, where those two civil service workers were being shown around the pitiful retirement accommodation they were just starting to realise was the only thing they were going to be able to afford in their old age, was particularly poignant, because it was exactly the same tone of anger and regret I had witnessed in that kitchen so many years earlier.)
The other thing is that I could never bring myself (or my wife) to live in the UK: It's getting closer and closer to African living standards every time I visit to see my parents, and I would know: I was born in what is now Zimbabwe, and I have many relatives in South Africa. I enjoy internet access speeds most of you won't see in the UK for at least another 10 years, and a general quality of life here in Switzerland that simply can't be had in the UK unless you're a multi-millionaire.
It was worth learning German for.
My beef with GCHQ is their supposed role in looking after UK interests: Exactly how does that work when the same UK government is practically falling over itself to allow as many immigrants (many of whom will be terrorists with EU passports) into the country as possible? I can understand Australia, New Zealand, Canada and the US. But I don't get why the UK is the only member of the Five Eyes that seems to think that the individual merit of applicants has abolutely no place in a modern immigration policy.