Ignore the negative comments above - you can choose to ignore the bad stuff and embrace the good stuff, it's the same wherever you go in the world.
There was this dude, I can't remember his name, who said:
"If a man is tired of London, he is tired of life. in London there is all that life can afford."
Or something along those lines anyway. Enjoy the amazing people you'll meet from all over the world, the great parks, the fantastic nightlife, beers on the floating bars on the Thames (which is where I'm off to in about 10 minutes!) and everything else it has to offer.
Just keep your hand on your wallet and try not to think about how much rent your paying