You will notice paralax at all distances except the one your scope is set for. As mentioned above that is probably 100 yards. The amount of paralax will vary based on distance and the properties of your scope. You have 2 choices. Practice getting your eye in exactly the same place relative to your scope every shot. ( not very easy ) Or buy a scope with paralax adjustment. Either an adjustable objective or a side focus adjustment. Most companies offer some models with paralax adjustment.
You can't fix stupid....however ignorance can be cured through education!