broken apple taste

I'm starting to wonder if something damaged my ability to taste apples. I've been systematically trying a bunch of different varieties, and they all register as "crisp, moist", some a bit sweeter than others, none sour or tart. Okay, so then I just tried a Granny Smith apple -- famously sour. Nope. Maaaaybe slightly sourer than the others, but I feel that in a blind taste test I'd say "just another bland apple."

Can I still taste sour things? Oh sure, like diluted lemon juice.

Maybe drinking diluted lemon juice raised my sour threshold? But I've been doing that only recently, while I've been feeling apples were bland for the past few years, and for some unclear reason stopped buying them regularly years before that.

Maybe apples just suck when you're used to pigging out on clementines and berries?

But I remember actively liking Braeburn and Pink Lady apples when I first encountered them...