"Realizing" is better. "Knowing" seems like you didn't ask the questions by yourself, like somebody else wrote them. Clear? :)

@Florence - i am not suggesting you help those needing help in English - but I am sure you are an expert in some language? And maybe there are one or two who might need your help there? At least you could probably help them to know what questions to ask :)))

@ Ralph, Haha...My English is not good enough to help others, but you are right, there is no point making excuses to defend myself, I should try to make up for it in future:-)

The most natural option for me would actually be: "I have asked over 200 questions on ITALKI without even realising it." Remember in 'proper' English we use 's' instead of the American variation which uses 'z' in words ending ise/ize. I think most spell checkers default to the American English, so watch out!

And how many people have you helped to answer their own questions?