The number on the weight is not the resistance.

It is a little more complicated than that. When we learn an exercise for the sake of executing the motion only, we forget the actual purpose of the exercise.
Do we want to focus on the movement or the muscle? Do you know which muscle you want to work on with each exercise you choose to do? Now what about the
resistance? Have you noticed that the same weight feels heavier in different positions?

It is not the number, it is where it is applied and how fast it is moved.

Where you decide to use the force will determine the actual resistance to the joint you are focusing on in an exercise. Holding a dumbbell straight out to your side feels different than bringing that same dumbbell overhead. Try it and notice how the weight feels lighter as you move from a horizontal (side) to a more vertical (overhead) position with the dumbbell. Now, add speed to the equation and it gets more interesting. Resistance can potentially increase or decrease depending on how fast you are moving the dumbbell.

From yoga and pilates to power lifting and other sports, it all boils down to the resistance and force on the joints resulting in adaptation. So, next time you are golfing or exercising in the gym, stop for a second to think about all the above.