I'm no roulette player, but I think every spin of the wheel is different that the previous, even if it drops on the same number.
The wheel and the ball are free-flowing in opposite directions.
The only cheat or edge I could think of in roulette, is when the operator can spin the wheel at the same speed each time and spin the ball at the precise moment with the same force each time.
Now talking about myths...I think most myths are passed down from parents or adults to children/younger people.
Knocking on wood I picked up either from my mother or from school.
As well as in school; the famed "koodies" that a boy or girl thinks they get for touching the other (usually a kiss on the cheek thing).
Finding a penny heads up, pick it up for good luck. I do that too. I usually find another penny or coin that day or the next time I'm out walking. So it could be a true myth in that perspective.