Puerto Vallarta (often referred to as Vallarta or just PV) is known for its friendly atmosphere, so it's not surprising that it attracts a lot of tourists. Many of the expats you'll meet here started out as tourists. The ones I spoke to told me they came here on vacation but realized pretty soon that they didn't want to leave. As soon as they went home, they changed their lives to move here. You can't get a better stamp of approval than that.
According to the "critical period hypothesis," it's easier to learn a language before the age of 13. That theory says that's when you have a better chance of achieving fluency and being accent-free. When I started studying Spanish two-and-a-half years ago, I was already 40 years past that window, so I wasn't sure how my attempts to learn Spanish would play out.
Some people go on vacation to a new country and fall in love with the place, then go home, quit their jobs and pack up all their worldly belongings to move there.