Haha I am glad that it seems that some rules are lost on native speakers just like English native speakers.

Like I recently read a joke from Russian Word of the Day about natives ordering одно кофе rather than один.

So many things I have learnt about basic English since trying to learn Russian. I mean my typing on here is rather lax as it is, and just follows my train of thought but for example I never knew how to use an apostrophe after the s, as in the pupils' book rather than the pupil's, until two days ago. And I'm born in England. Not because it's hard to understand, just got skipped over in lesson. And an elephant... a chair! I always say it but never knew it was "an" rather than "a" because of the noun starting with a vowel. Crazy I've learnt pre double digit English by looking up Russian translations.