Life is the sum of all experiences had over a string of years, months and days. The days themselves are influenced by activities and decisions made each hour. Every hour counts and contributes to what will be our lives eventually. The behavior is cumulative, gradual and carries forward, that is, the hours in the past impact the hours in the present and in ones to come in the future. I imagine it is like a smooth wave function, much like everything else in nature.
Pick carefully how you choose to spend this hour, because it will impact many more hours to come in your life, and eventually contribute to the definition of your life itself. One is unable to wipe out the impact of the past hours just by an instantaneous change in thinking, a decision, or by an abrupt change in behavior (imagine a step curve). Changes in life can only be affected with consistent action towards the intended change every hour, which eventually results in a gradual progression towards the outcome of the change, like a wave.