If you could start your life over, what would you do differently?

Shannon Bryant, of Pasadena, Texas, would change how she treated her mother as a teenager.

At 14, Bryant was rebellious and filled with angst. She skipped school, hung out with the wrong crowd and didn’t always obey the law. Her defiant behavior only intensified after her mom, Janet, was diagnosed with liver cancer.

“I was horrible to my mother when she was sick,” Bryant, now 26, acknowledged. “I blamed her for getting cancer. That’s when I started treating her the worst, because I didn’t know what was going to happen, and I didn’t know if she was going to make a comeback.”

Bryant’s mom fought cancer for two years, undergoing chemotherapy, radiation therapy and surgery. But it wasn’t enough. A couple of weeks before her mom’s death, Bryant, who by that time had moved in with her dad, went to visit her mom in home hospice care. With her mom bedridden and practically comatose, Bryant crawled into bed next to her and apologized for everything.

“I told her I was sorry for all the mean things I said to her and how I acted,” Bryant said. “I knew she could hear me even though she couldn’t respond.”

Although Bryant made final amends, years passed before she could break free from her crippling sense of regret.

Forgive yourself

To err is human, to forgive divine, wrote English poet Alexander Pope. When it comes to regret, the person you most often must forgive is yourself. A recent study from Baylor University found that making amends with individuals you’ve wronged increases your likelihood of self-forgiveness. The research also showed that the guiltier respondents felt, and the more grave their wrongdoings, the less likely they were to self-forgive.

Regrets are a natural part of life, said Judith Orloff, psychiatrist and author of “The Ecstasy of Surrender: 12 Surprising Ways Letting Go Can Empower Your Life” (Harmony Books). They aren’t reasons to beat yourself up, but experiences to learn from.

Orloff said the “in the moment” regrets, like yelling at your spouse or avoiding a friend’s phone call, act as the best learning opportunities. If you get into an impassioned argument with your husband, scream a nasty remark and feel guilty afterward, don’t dwell on it. Identify how your behavior escalated out of control, say I’m sorry, and keep this lesson in mind for next time.

It’s those lifelong regrets — like never having children or not going to college — that are hardest to deal with, Or­loff admits, but the key is to not obsess over them. Once you recognize why you made a past decision, accept it, let it go and live the life you have to the fullest, she said.

Dale Genetti, relationship and marriage life coach, eventually adopted this attitude after realizing she walked out on the man of her dreams. Married in 1990, Genetti was deeply infatuated with her husband at first, but in their third year of marriage, she started to second-guess her feelings and question whether he loved her.

“[The relationship] just started to fall flat for me,” she said. The couple tried counseling, to no avail. One day while her husband was gone, Genetti packed up her belongings and moved to Atlanta. About six months later, she was in the midst of reading the 1990s bestseller “Men Are From Mars, Women Are From Venus” when she had a light-bulb moment. A part in the book about how men exhibit their love helped Genetti see that her ex-husband had in fact loved her; he simply showed it in ways incongruent with what she preferred.

“He was doing all the guy stuff to demonstrate what a great husband he was, and my love tank was depleting because I wasn’t getting affirmations or a sense of touch,” Genetti said. “If I knew then what I know now, I wouldn’t be divorced.”

Genetti, who for years worked as a flight attendant, partly credits the relationship for the reason she changed careers to become a relationship coach. She wants to help others avoid her mistake.

Romance tops the list

In a 2011 study, Neal Roese, a psychologist and professor of marketing at Kellogg School of Management at Northwestern University, found that the most common regret among American adults tends to involve romance. This was overwhelmingly true for women, with about 44 percent of female respondents recalling romance regrets, compared to 19 percent of men. Other common regrets included family matters (16 percent), education (13 percent), career (12 percent), finance (10 percent) and parenting (9 percent).

In a 2012 follow-up study, Roese discovered the most notable regrets in people’s lives are generally tied to humans’ inherent need to belong.

“People who have the biggest regrets in their lives either missed out on a relationship or lost contact with a friend,” Roese said.