Idea for a Card Trick that would be incredibly easy to understand and do-

Note: Because I find most card tricks too complicated to understand I thought I would try and think up a card trick that someone as dumb as me could do.
The Trick:
Get a deck of cards where the backs of all the cards are symmetrical but the faces are not.
Then fan out the cards face down and ask someone to pick a card, take it from the deck and, not showing it to you, memorize it.
While they're doing that turn the face down pack of cards upside down.
Now ask them to put their card back on the top of the deck and then shuffle the cards anyway you wish.
Now tell them that you will easily be able to tell which card is the one they picked.
Now look at the face up deck of cards.
Remember that you turned the deck upside down so all the cards, because the faces are not symmetrical, should be upside down apart from the card they picked which should be the right way up.
Note: This card trick may already exist. I don't know. All I know is that I've looked through lots of magic books and have never come across a card trick as simple as this. Some of the card tricks described in magic books are several pages long.