When I was about 12, I asked my father, "Dad, how come you never complain?" His response was the most important lesson anyone has ever taught me. He said, "Martin, the Nazis took five years from my life. I won't give them one minute more. Martin, never look back; always move forward."

That lesson was so valuable because every time I'm tempted to look back on the bad things that have happened to me, I immediately think of my father, then say "Stop." Then I ask myself, "What's the next positive thing I can do?" That has stood me in good stead.

My clients have also found it valuable--especially those who have had a lot of psychotherapy. Therapy encourages them to look back. Often, that entails blaming their current problems on their past: being ignored or abused by parents, being dumped by a husband, being shunned because of race, gender, or sexual orientation. Therapy may have given them insight into themselves, but their life isn't necessarily better. In fact, for the good that therapy often does, I've found that many of my therapized clients have been made inert from all the analysis of their past pain. Like a muscle that gets bigger the more it's used, past hurts sometimes take up an ever larger part of people's consciousness, until it turns them into what I call therapy paralytics.

My father's approach--constantly substituting forward movement for backward thoughts--made his painful bad memories an ever smaller part of his consciousness. I'm sure he was often tempted to think back to the Holocaust, but he filled his life with thoughts about upcoming work, relationships, hobbies, and fun.

I've read, listened to, and watched many interviews of highly successful people. The vast majority of them minimize the impact of the bad in their past. They're always saying things like, "I guess there probably was some racism, but I just didn't focus on that."

I've recently added a phrase to my father's dictum: "Don't look sideways." I know people who don't live in the past but are awfully worried about the other guy. They're saddled with thoughts like, "I'll never be as successful as my brother." Or "I feel so bad that my fellow classmates are all investment bankers, lawyers, and the like, with nice houses and nice cars, and I'm still trying to figure out what I want to be when I grow up." That sideways thinking is no more productive than looking backward. Don't compare yourself with anyone or judge yourself by societal norms. Simply ask yourself, "What is the next positive step I can take?"

So, never look back; never look sideways; always move forward. I can offer you no better advice.