This says so much with so few words. If we think about water dripping on a stone we don't immediately think that the water will eventually shape the stone. Clearly the water is much softer than the stone and its dripping does not carry much force with it.

What the dripping water is doing day in day out, hour by hour, and minute by minute is taking consistent action. Far to often we may put off taking action because we do not feel that our actions will carry the force and power with it necessary to achieve our goals. The key is that we must act consistently. In most cases trying something once simply isn't enough. As the Spanish proverb so eloquently states, “An oak is not felled at one blow”

If we act with the consistency of dripping water we will shape our destiny.

Constant dripping hollows out a stone. – Lucretius