A childhood belief about magic tricks

When I was little, my dad used to do a 'magic trick' where he would get me to pick a card, seemingly at random, from the pack then lead me on a warmer/colder search for my card which would turn up in a seemingly impossible place such as CD case on the other side of the room or his back pocket. I would always ask him to repeat it, only to be told he had to have time to 'store up some magic'. What was really happening was that we had a set of two decks with different colured backs and he was hiding one card in advance and forcing the same one from the other deck, I just never noticed the different colour. I genuinely believed my dad had magical powers of teleportation and only found out the truth when he told me at the age of about 11 out of guilt.