Wisdom can come from unlikely places. The older I get, the more I recognize that as a piece of wisdom in and of itself.

Lately my learnings have come from a recurring shoulder injury that has me working to correct a weakness throughout the left side of my body. When I neglect my physical therapy exercises or allow ego to overtake common sense in my workouts, then the injury reasserts itself.

The discomfort has inspired me to break the habit of physically leading with — or favoring — my right side.

Quickly, without thinking, clasp your hands. If you are right handed, as I am, your right hand will fold over your left, with the right thumb on top. If you’re left handed, most likely the opposite will be true.

Back in my days as a fitness instructor, I would talk with my students about our tendency to lead with our dominant side whenever we are walking, weight lifting or simply crossing our arms or legs. That practice builds strength in one side of our bodies — and perpetuates weakness in the other.

Like any unconscious or unhealthy habit, favoring my right side has caught up with me in middle age. And so, as I work to reverse the practice, I’ve been pondering which habits of thinking — assumptions, judgments and beliefs — are similarly automatic.

Leading with my left

Regrets are all too common at this stage of middle age — the point at which we have “more yesterdays than tomorrows,” as Bill Clinton said at the Democratic National Convention earlier this week.

• One friend ruminates about why he has married two different women who have never measured up to a passionate love interest of his youth.
• Many women regret the choices inherent in combining children and a career.
• I’ve had to reconcile that I am too old to become a lawyer or a political reporter, knowing that I would have done well at either profession.

Leading with my left — developing new patterns of thinking — means I don’t allow myself to get stuck in the rut of regrets.

Leading with my left means I suppress my irritation when a friend who has depression doesn’t return my voicemail or text messages. Instead I talk to a man who has his depressive tendencies under control, and he suggests some kindhearted questions I might pose to her.

Leading with my left means trusting my gut — and my outrage — when a financial adviser with whom I had intended to invest my retirement savings tells me that my 26-year-old son lacks a “real job.” My son, a college graduate, works full time. He has health insurance and a 401(k) plan. He recently got promoted. He works hard at his craft.

But his job is at a brewery, and that apparently lacks cachet and aspiration for a woman who makes her living among society’s fortunate few. Her comment gnaws at me. “Is it important that your financial adviser shares your values?” I finally ask two friends.

Leading with my left means recognizing that I already know the answer. “All work is honorable,” I told my boys when they were young. I am proud of my son, and that’s the only message he will hear from me.

The underside of strength

An industrial psychologist introduced me to the notion of a “shadow side” of our perceived strengths. In yoga, we call it the marriage of opposites: yin and yang. If one part of us dominates — whether it’s a character trait or one side of our body — we will eventually fall out of balance.

I’m an ENTJ in the Myers-Briggs Type Indicator (MBTI), a decisive personality type that gets a lot done, but sometimes at the expense of others. In the two years since I stepped away from management, I have learned to exert influence rather than exercise authority and to value collaboration more than control.

Leading with my left at work is not always easy, but the softening seems particularly suited to middle age. “As my energy started to change, the energy that I got back from other people started to change,” said former police officer and co-founder of the Center for Mindfulness and Justice Cheri Maples in a recent episode of On Being.

In the case of my 91-year-old father, leading with my left has meant becoming a more present daughter in the time that he has left. For years my dad and I have kept a respectful distance, despite our similar strengths and countervailing weaknesses:

• A strong moral code that constructs rigid definitions of right and wrong.
• A love of fitness and exercise that judges weight gain as lack of discipline.
• A sense of duty and responsibility that leads us to rely on work for self-esteem and recognition.

I spent the first afternoon of my summer vacation helping Dad sort through a lifetime of his beloved books. As he and my stepmother prepared to leave their house for the security and convenience of a seniors’ apartment, I stepped forward for the one way I could help.

An English major in college, I love libraries and bookstores. I don’t own an e-reader, and it has never occurred to me to buy one. Sorting through and boxing up my father’s books allowed me insight into his thinking and character in a way that his stoic, taciturn nature would not allow.

Leading with my left, in the twilight of Dad’s life, means letting go: of the blame for circumstances that were not his fault, of the insecurity that said he never really loved me. Leading with my left means being, today, the daughter I wish I had been for decades — forgiving him, forgiving myself, for being human.