My parents had a rule that we couldn't wake them until 7 a.m. on Christmas morning, and they told us, if we went downstairs before them, Santa would take all our presents back. Of course, poor them, from 5-7 a.m. they had to listen to the four of us sitting outside their bedroom doro trying to be quiet. It always ended up with one of us yelling "Shhh!!! You're gonna wake Mom and Dad!" I'm sure they were rolling on the floor laughing so hard.
When I was a kid I came home and was upset that my friend said the Easter bunny didn't exist. So to convince us, my parents stayed up all night on Easter eve cutting out and painting cardboard bunny prints, then they left them all over the house leadin to our easter baskets. Boy we were convinced! Of course, it didn't occur to me until years later that you can't usually pick up a footprint and carry it around with you!
When I was very young 3 years old or so, my Dad accidentally sat me in front of the TV while Salem's Lot was on. It was just before the woman sat up on the autopsy table and attacked the coroner. Of course, I was terrified. So to comfort me, my Dad taught me how to make a cross with my fingers to ward off vampires. We practiced making the cross and he would be the vampire and fall over dead, complete with gorans and dramatic death movements and noises. Then I was the vampire, and he woudl make the cross, so I could "die". Then he told me that vampires hated light and would fall over dead whenever a light came on around them. Unfortunately, I took this one to heart. For a year after that I would fall over "dead" when someone turned on a light...in church, the grocery store, restauarants...LOL