You have plenty to hide. Fortunately, nobody cares about you, at least not at the moment.
Put another way: the question of whether or not you have "something to hide" isn't yours to answer. Your user name is German; you should understand this better than anyone.
Can you post your credit card information here? If not, congrats, you have something to hide.
Privacy is a human right that needs no justification.
Why do you care about what I do if you aren't a snooping pervert?
What's your address and phone number? We can help you understand.