The first law of motion is that which is in motion tends to stay in motion and that which is at rest tends to stay at rest. Some kind of force is needed to change the motion or lack thereof.
The force needed to bring a self imposed challenge; a dream or a wish into motion is what takes the most force. Although that starting force is often hard to find once it is in motion it will likely stay in motion and so the biggest challenge in life, is not in completing a self-imposed challenge but in beginning it.
