I just learned a british grammar complexity that I didn't know existed. In fact, the very first clause in that last sentence was wrong, because it should have been "I've just learned".

Apparently the British preference for the perfect present tense is actually a rule that conveys important meaning that doesn't exist in america. Because when a brit chooses which tense to use ("i did you" vs "I've done you"), it is actually conveying some relevant information: the completed action's ongoing and present relevance.

>I did you
This would be the form an american would always use. Simplified, negrified, brutish. A brit would only use this form to indicate that he did you so far in the past that it no longer has relevance
>I've done you
An american would never say this. When a brit chooses this form, he is not only communicating that you've been done, but that the consequences of you being done are still ongoing and relevant