Where I got sober, a few of the oldtimers used to say "I came for my drinking, but stayed for my thinking." The process of working though the first nine steps to the best of my ability deflated my ego which in turn made room for my Higher Power to work in my life and remove the obsession to drink. I was able to discover some big chunks of truth about myself and clean up most of the wreckage of my past. But I still have plenty of "stinking thinking" down in my subconscious that can bubble up to the surface and cause me to say and do things that I regret. The 10th step helps me become aware of how these false and worthless ideas are robbing me of my peace of mind.
Staying sober is no longer a daily challenge for me, but living with poise and serenity is. When I churn in anger, lose sleep to a resentment, or project a doomsday scenerio in fear I can be sure that some old idea is at work. When I am reacting from anger, fear or guilt, I forfeit any any chance at authentic happiness for as long as it take me to return to sanity.
When I work step 10 regularly, I pay attention to to my life instead of sleepwalking through it. I begin to see patterns to my reactions. I see how self will, driven by "100 forms of fear," keeps me in a prison of my own making. Eventually I get "sick and tired" of giving away my serenity and I become ready and willing to do whatever it takes not to live this way any more. I believe this is what "entirely ready" means in step six.