Forget wrinkles and gray hair. There are lots of reasons to celebrate each time you add a candle to your birthday cake. You gain wisdom and many other benefits with age.

Here's a look at just a few of the good things that come with growing older.

An ability to manage social conflicts

So much of the drama of youth goes out the window with the wisdom of maturity. As we age, we're able to look at social situations and manage them a little more wisely.

Researchers at the University of Michigan put this to the test. For their study published in the journal PNAS, they asked 200 participants to read "Dear Abby" letters and offer up their best advice. People in their 60s were better than their younger counterparts at coming up with multiple outcomes for a social conflict and were better at imagining different points of view, while preferring solutions that involved compromise.

An encyclopedic knowledge

When you're young, you're learning new things all the time. You're memorizing math formulas and spelling words, learning historical events and scientific equations. Your brain is a sponge.

When you're older, you use what you know.

Psychologists often refer to two main types of intelligence: fluid and crystallized. Fluid intelligence is someone's ability to solve problems, learn new things and use logical thinking in unfamiliar situations.

With fluid intelligence, you don't use prior knowledge to help you figure things out. You might use fluid intelligence when solving a puzzle or doing something creative, like playing an instrument for the first time. Fluid intelligence typically peaks in young adulthood and then slowly declines.

Crystallized intelligence, however, is based on what you've learned in the past. It makes use of information and skills you've already mastered. You use it in situations like reading comprehension and vocabulary tests. Because you just keep collecting knowledge, crystallized intelligence just keeps increasing as you get older.

A greater sense of well-being

senior couple walking dog in the countryside Older people are usually happier because they have less anxiety and stress. (Photo: Monkey Business Images/Shutterstock)

It's known as the paradox of aging: The older people get, often the happier they become.

In one study, researchers surveyed more than 1,500 San Diego residents between the ages of 21 and 99, and found that those in their 20s were the most stressed out and depressed, while those in their 90s were the most content.

"The consistency was really striking," Dilip Jeste, director of the UC San Diego Center for Healthy Aging and senior author of the study, told the Los Angeles Times. "People who were in older life were happier, more satisfied, less depressed, had less anxiety and less perceived stress than younger respondents."

Other studies have also looked at the link between aging and happiness. They've found that as we get older, we become more trusting, and people who trust others are more likely to be happier.

Older people often have increased financial well-being, so that takes the monetary element out of the stress equation. In addition, they tend to let go of negative emotions and focus on positive events.

An immunity window

Little kids get sick all the time. They pass colds around at school and catch everything because their growing immune systems are still developing. The good news is that as you age, your adult immune system recognizes these microbes as they invade your body and forms an "immune memory."

But there's an ideal time frame, John Upham from the University of Queensland tells the BBC.

"It does begin to drop off in your 70s or 80s, but there's a bit of a sweet spot for people — particularly from your 40s through to your late 60s and early 70s — where the immune system remembers the viruses experienced over the years."

During that time, you might be less likely to catch colds and get sick.

Becoming more agreeable

two senior women looking at a phone People get less grumpy as they age. (Photo: Olena Yakobchuk/Shutterstock)

Forget about getting older and crankier. As you age, there's a good chance you'll become more agreeable and easier to get along with.

In a study of more than 132,000 people ages 21 to 60, researchers at the University of California, Berkeley, looked at overall trends in personality traits. They found that participants started to become the most agreeable in their 30s and continued to improve throughout their 60s, according to the American Psychological Association.

This even happened among men, which debunks the concept of "grumpy old men," said lead researcher and psychologist Sanjay Srivastava, Ph.D.

Fewer migraines

If you suffered from migraines most of your life, you may get a break as you get older.

If hormones are one of a woman's headache triggers, migraines can sometimes abate after menopause, according to the American Headache Society.

Only 10% of women and 5% of men over 70 still report migraines, reports WebMD. And if you still have a migraine then, it may come without actually headache pain. As people get older, some may only experience migraines as visual or sensory disturbances without any pain.

Less sweat

couple doing yoga at the park You won't be as sweaty when you exercise. (Photo: kudla/Shutterstock)

Hot flashes aside, you may sweat less as you age. (Well, technically, you sweat differently.)

With age, sweat glands shrink and there are fewer of them.

A study in the Journal of Applied Physiology found that women in their 20s sweat more than women in their 50s and 60s. Researchers attributed the difference to either "a diminished response of the sweat glands to central and/or peripheral stimuli" or "an age-related structural alteration in the eccrine glands or surrounding skin cells."

Change in self-esteem

Long gone is the insecurity of youth. Self-esteem is highest right around age 60, research finds.

In a paper published in Psychological Bulletin, researchers analyzed 191 journal articles and dissertations on self-esteem that involved nearly 165,000 people. They found that self-esteem starts to grow between ages 4 and 11, then levels off in the early teenage years of 11 to 15.

"On average, self-esteem increases in early and middle childhood, remains constant (but does not decline) in adolescence, increases strongly in young adulthood, continues to increase in middle adulthood, peaks between age 60 and 70 years, and then declines in old age, with a sharper drop in very old age," they concluded.

That self-confidence stays strong for about a decade, then drops around age 90, often because of health reasons.

Less sweat, more self-esteem, fewer headaches and so much more? Sounds like a pretty good trade-off for a couple of laugh lines.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

8 good things that happen when you get older
From fewer migraines to more self-esteem, there are so many mental and physical benefits to growing old.