Its a matter of desire to learn and practice, just like anything else.
Being with a Mexican lady for years would be good motivation. But I’m sure eating burritos and chorizo has nothing to do with rolling Rs.

My brother-in-law cannot pass up a taco/burrito joint on a long trip but he is completely incapable of rolling his Rs. His wife is from Brazil and pronounces her r correctly, in this context. They have been married for about 2 decades. He still does not eat any spicy food but loves ketchup on his steaks. Takes all kind to keep life interesting. 😉