I just tell people I travel alot and my friends English from all over the world rubbed off on me.
I would actually say that for a longer time I have consciously avoided regional slang, as American colloquial English is not usually any close to academic English and it is very easy not to notice. But Europeans have no clue what you’re saying if you are simultaneously slurring words, completely altering sentence structure, using idioms, and complete slang.
So maybe it just gravitates towards an enunciated and generic international form of English? Skip a syllable and there it is.