Forbidden Fruit

After listening to my grandfather and parents speak a few minutes ago, I began to wonder why all the 'best' fruits seem to disappear. They were talking about how long it's been since they've seen this type of fig (not the sweet, seed filled type but something resembling a purple banana) and granddad said that it is supposed to be one of the most delicious types of fig and is found virtually nowhere anymore... Now why the hell is that?! How does it make any sense that the best fruits are always the rarest. And this isn't the first time I've heard it - there's hog-plums and special cherries and weird named fruits with soft, hairy exocarps. 

If a fruit is delicious, wouldn't you try to plant it  everywhere or keep a tree in you yard or something? 

That's when I began thinking... what if these fruits only became known as the best after they'd become rare, if everything was purely psychological. After not tasting them for tens of years, the brain, in memory, seems to just pick out the good qualities of said fruits and it exaggerates them. It's the concept of the forbidden fruit, literally. 

This was all just something I was thinking about. I don't know what its like in other places but here in T&T people seem to always want what they can't have, even if it's not a good as they think...