I was speaking to a 15-year-old native English speaker (in Australia), who referred to someone as her "best friend". Later, she revealed that this wasn't her only best friend. She had four best friends.
She couldn't understand why that was confusing to me (and I didn't want to get into a discussion about "best" being a superlative for "good").
Is this just one girl who is using the term unconventionally, or has the term "best friend" been softened to only mean "very good friend"? (Or even more extreme, has "best" been softened to only mean "good"?)