I've got a decent handful of international clients and I speak German and understand Spanish. I swear I've got more than one German client who is genuinely significantly friendlier and more agreeable when speaking in English than when speaking in German. Then I've got one Spanish client who seems to be a lot more direct when speaking in Spanish than in English... Add in cultural differences and it's a miracle the global economy functions as smoothly as it does.

At my old company our territories used to be really broad, but we finally had to tighten them up because of how different sales executives pitches had to be even between neighboring countries, where if you aren't used to dealing with them specifically you can be next to useless. Like, I had eastern Asia as one of my territories when I first started at my old company. Had always prided myself on being able to overcome any objection, and was in a meeting where one of the guys was trying to take 1 more week to talk more to our competitor even though his team wanted to move forward. That's a problem I've dealt with 100 times, no big deal, so I ask why he needs to work with them more first when we are beating them on every box. His response is "because I said I would give them a strong chance, so to stop now would dishonor the spirit of my ancestors." At which point my only option is to go get sushi because I got nothing for objections regarding the honor of one's ancestral spirits.