While in the US, people would often tell me that my style of dress and my accent was hard to place, which I always found a bit odd since I was born/raised in the US (to a long line of Americans). And now after 10 yrs abroad, following that period, I can only guess I've got better at hiding it, merely through osmosis.

In my time abroad, I've become good enough at Brazilian Portuguese (my 2nd language, learned as an adult) that people in Portugal, where I've been living, often think I'm from Brazil. I always mention quite early on that I'm from the US but, nonetheless, I'm still intrigued with the idea of disguising oneself.

Linguistically, I'm highly doubtful that one can reach C2 status (that is, consistently sounding like a native) in a second language learned as an adult. Of the Brazilians I met in the States, I paid attention to how old they were when they arrived stateside, and judged their cultural/linguistic knowledge with people who were born in Brazil and never left. Anecdotally, I found the age of assimilation (of their home culture/language) was around 16. That is to say, if they arrived in the US at age 14, for example, they'd turn out to be more American than Brazilian by their early 20s. But I wonder how that can be entirely true if I myself don't seem to fit in that box, regarding my American qualities.