When you get to Lilycove city, if you go all the way over to that house where the cove part starts. There is a man in a blackish suit that walks back and forth around that area, if you go talk to him he'll explain about this weird 'berry to a T' thing. Then every so often he will give you a berry, it may not be much but eventually, he'll give you rare berries, and you can sell them at high prices. And some of them also have good effects on Pokemon. So, have fun talking to a dude that gives you weird berries that remind people of their past and future. Even if you don't know what your future holds.