Last year I listed 12 things I knew at age 50 that I wish I had known at 25. Now I'm a year older. And if I'm not wiser, at least I'm a bit more experienced. So here are 12 really stupid things I've done that I never want to do again. Maybe you've done some of them, too. But I'll bet we'd both be happier if we didn't...

1. Compare. Ever heard the saying "Compare and despair"? Comparing yourself to someone else usually means that you imagine the other person is better off, more satisfied -- in a word, happier. But here's the problem: We end up comparing what we know about our life, which is a mixed bag of good and bad, with a fantasy of someone else's supposedly "perfect" life. Why do we do this? Because we know all about our own problems, but other people's problems are harder to see. As a result, our real life always loses out. That leads to despair. Besides, there's probably someone comparing his or her life to your supposedly perfect one -- which shows you how ridiculous it all is.

2. "Should" on Yourself. It's devilishly easy to imagine yourself making a choice that would have taken you to a different place in your life. I should have married this person; I should have taken that job; I should have moved; I should have blah, blah, blah. This is called "shoulding all over yourself." (Say it aloud and the negative meaning becomes clearer.) Reflecting on our choices is an important way to grow, but you can't live your real life if you're busy living in your "should have" life. You'll end up torturing yourself. Jesus of Nazareth once said you can't serve two masters. You can't live two lives either.

3. Get People to Like You. I spent all of my teens, most of my 20s, a great deal of my 30s and too much of my 40s trying to get people to like me. But forcing people's affection rarely works. Plus, it takes too much energy to tailor yourself to what you think people will like (which is impossible to figure out anyway). Your true friends like you already. Be open to change and growth by all means; but treasure friends who love you for who you are. St. Francis de Sales, a lighthearted 17th-century saint, once said: "Be who you are and be that perfectly well."

4. Interrupt. We all think we're good listeners. We're not. Many of us are absolutely terrible listeners, impatiently waiting for our turn to speak, confident that our next utterance is the solution to everyone's problems or the most interesting of all the commentary yet offered. But you can't contribute intelligently to any conversation if you're not listening what the other person is saying. Interrupting someone says, "I have no interest in even letting you finish your thought." As my sister tells her children, you have two ears and one mouth for a reason.

5. Worry About How You Look. I cut myself shaving: Is the blood still showing? I have a zit: Is it getting bigger or going away? I need a haircut: Should I get one today or tomorrow? Are these pants too short? Too long? Who cares? Sure, you need to look presentable for your job and a decent appearance is a sign of respect to those around you. But if your friends are overly concerned about your clothes, and judge you on that basis, they may not be the best friends for you. And who in their right mind cares what strangers think about your clothes, unless you're a fashion model? Spend less time thinking about your outside and more about your inside.

6. Work Constantly. We are immersed in a culture of productivity, which says that we are what we do. That's why the first question out of someone's mouth upon meeting a stranger is often "So what do you do?" We also measure ourselves by how much money we have, or make. Thus, discussions about salary are a big taboo. You can ask someone about their facelift or their divorce, but not what they earn. Why? Because it's the default measure of worth, and it ruthlessly places people on a social ladder. If someone makes more than we do, we may feel "less than." Look, everyone's got to work. But if value is gauged by wealth, then when we make less, we feel less valuable as human beings, which is tragic. Nelson Mandela didn't make much money when he was imprisoned in South Africa; was he less valuable? Plus, if we are what we do, when we're not working we're nothing. This kind of thinking creates a skewed measure of "value." Stop driving yourself nuts with the trap of constant work.

7. Fail to Give People a Break. Hey, surly person behind the drugstore counter: Why didn't you say thanks when you handed me my change? Hey, barista, why are you being so rude? Stop and think. Maybe it's because they're underpaid; they hate their low-paying job; their mother is dying. Remember that behind those frowning faces are full lives. Remember too, that all these people all beloved creatures of God, with their own human dignity, and holy in their own way -- yes, holy. When the Book of Genesis said that God looked at everything and said, "It was good," he meant people, too. Even the angry barista. Give them their dignity by giving them a break.

8. Complain About Minor Illnesses. If you've got a serious or chronic illness, you need to share your struggles and frustrations with your physician, with friends and family, or even a therapist. You need support. But do you have a cold that has hung on for days and makes you phlegmy? When you bend over like this does your back ache because you pulled a muscle in the gym? No one really wants to hear about minor illnesses. Everyone gets sick, for Pete's sake. In the words of the great prophets, suck it up.

9. Be a Jerk. You're tired. You're rushed. You've got a cold. You're late. You're angry about something your boss said. Yes, you're miserable. That doesn't mean you have to be a jerk to everyone else. It really doesn't. Sure, share your frustrations and struggles with close friends, but don't make everyone else's life more miserable by passing on your misery. Once, I joked to a friend, "Boy, my life is such a cross!" "Yes," he said, "But for you or others?"

10. Avoid Doing the Right Thing. It's no fun to call a friend who is in a bad mood because she's lost her job. It's no fun to take responsibility for making a mistake. It's no fun to speak out against racism, sexism or homophobia and stand up for those being mocked. It's not fun, it takes effort; but you know it's the right thing to do. Do it anyway. If you don't, you'll feel terrible about yourself, and that's really no fun.

11. Make Fun of People. Nothing brings me lower than a few minutes of mocking another person. (Particularly if the person is not present.) But the snappy putdown has a high value in our culture, and famous snubs (say, of one famous writer to another) are repeated, and treasured like beautiful jewels. Much of our current political climate consists of politicians mocking people in the other party. (That's been a big help in this country, hasn't it?) Malicious speech is an easy way to wound. If you feel like you're powerless against badmouthing someone, ask yourself three questions when it comes to commenting on another: Is it kind? Is it necessary? Is it true?

12. Be Hard on Yourself. One of my Jesuit mentors used to say, "Be easy with yourself, Jim." If you're reading this list, and taking it at all seriously, you may be beating yourself up about stupid things that you've done in the past. (Believe me, my list is just as long as yours.) But you also want to change yourself, which is good. So be careful to "trust in the slow work of God," as the Jesuit Pierre Teilhard de Chardin used to say. (He was also a paleontologist, so he knew about things moving really slowly.) Or if you don't believe in God, trust in slow work, period.

If you ever get discouraged about your rate of change, just think about trees -- yes, trees. In the summer they're green. In the fall they're red. And no one sees them change.

James Martin, SJ is a Jesuit priest, culture editor of America and author of "Between Heaven and Mirth: Why Joy, Humor and Laughter are at the Heart of the Spiritual Life."