[bynormous]

I was intrigued in your experience as a polygot and was buying your arguments until I read your suggestion to listen to guides then that completely reversed it because almost all the many many guides I've had are definitely not fluent in their non-native language in the same way children gain fluency. Most have broken language in the same way older immigrants have broken language despite the fact that are forced to navigate in their adopted language full-time.

[recuter]

Have to start your search somewhere. Watch out for an older distinguished-looking gentleman giving proper tours, not the fellows that accost you at the exit of the bus/train station with a few simple sentences.

If I was a researcher with no travel budget I'd try cross referencing a list of medium-small touristy towns (like Cusco) with decades that had upticks in tourism and a very bad local economy. Narrow it down to above-average income college grads and start asking them if they are or know of a polyglot. Can probably get pretty far with nothing but Facebook.

Just a guess, maybe I'm wrong about this pattern. Let me know what you find out. ;)

Edit: I was also intrigued by your comment until I read "in the same way older immigrants have broken language" - this is indeed the common but rather narrow experience. I don't think I'll be able to convince you of anything. Best assume you are corresponding with the Loch ness monster.

[bynormous]

My work requires me to travel with guides, I have no idea if they are all above average income 'gentlemens' as you say (before you edited it out) so I can't really comment on that. I'm an immigrant myself along with my community so there's that. If you consider that a 'narrow' view not sure what more to say. There's a difference between fluency and native-like fluency that kids obtain. I would love you to post recordings of you speaking and ask the public to see if they can tell if you're a native speaker or not because I genuinely am curious.