A little while ago (not joking) i was doing some tricks with spongeballs to this kid at my local soccer fields (i swear i'm not kidding) i decided that i wanted to do a card trick or two (ready?) i TOOK OUT the deck of cards and the kid said "i've seen this trick before"
I actually get this a lot. (Actually never got it like you where I just took a deck out and they said it) Anyway, at least 5 times, it happened that I say: "Here, pick any card". and they go: "Oh, I know this trick". And then I'd have to explain that there are many tricks that begin with "pick a card".
One time, I was doing ambitious card to a friend of a friend sorta... anyway, after I do it, (I finished off with Fallen, by Daniel Garcia) He tells me that he's into magic and knows most of the sleights. He then pretty much explains the whole trick fairly well without giving the exact method of how I did it, but with popular methods of doing ACR. And then for the last part, where I had done Fallen, he takes the deck and "shows" me how I did it: pulling out one card at a time really quickly and pushing it under his card. And then he actually demonstrated it slowly. I just laughed and was like DEAR GOD MAN, I can't move my fingers that fast! And he was so sure of himself: "Yeah, I've seen that last one before. I can't do it, but like all you do is hide this part, pull out the card with this finger, and push it in while pressing on here."
When I talked to him after, he tells me that he reads books and watches teaching videos just for fun, just so that he knows how all tricks work. :\