Used to be (5+ years ago) I'd find fresh mangos in the market for a month or 6 weeks a couple of times a year. I assumed this corresponded to the two mango seasons north and south of the equator. Anyway, the mangos weren't always available, but when they were, they were wonderful. Sure, you'd get a bad one every once in a while, but basically they were heaven.
Now, they're available virtually year round, and it's nearly impossible to find an edible one. OK, that's an exaggeration, but a really high percentage of them are stringy, underripe, overripe, bruised and/or bleeding. There's nothing more depressing to me than a bad mango (OK, another exaggeration), and I get way too many of them lately.