I'm actually doing an English course/study so it's kind of expected haha. That aside I've talked (well.. written) English since I was 7 (runescape ftw) and then spoken it since 12. 

Rule of the thumb for Dutch people in English is:

1. The accent is terrible, always. Every Dutch person has a shit accent.
2. You are either REALLY good or REALLY bad at English, there's not really an inbetween.