How have you learnt English so well? I don't mean people living in the UK (where you'd pick it up) but in other countries? Were you taught well at school or did you learn from American TV? Did you study abroad or have mixed nationality parents?
I live abroad and it fascinates me that English is the common language. I'm surrounded by Greeks, Russians, Arabs, Slovakians, Serbians, Dutch, Swedish, German and French et al yet we all communicate in English.