Editor's note: Peggy Drexler is the author of "Our Fathers, Ourselves: Daughters, Fathers, and the Changing American Family" and "Raising Boys Without Men." She is an assistant professor of psychology at Weill Cornell Medical College of Cornell University and a former gender scholar at Stanford University. Join her on Facebook and follow her on Twitter @drpeggydrexler.
(CNN) -- On Friday, first lady Michelle Obama turns 50, and the party, we hear, is going to be fantastic. There's even a rumor Beyoncé will perform. The first lady proves 50 is certainly no signifier of slowing down or calling it quits, even if the AARP does consider you worthy of membership. The list of other powerful, in-their-prime women and men over 50 is miles long.
Chances are Brad Pitt, Rita Wilson, Oprah Winfrey, Janet Napolitano, Daniel Day Lewis, Meg Whitman, and their many, many cohorts can attest to some of the pros of turning the Big 5-0, among them:
1) You can forget about contraception. Probably. Although it is biologically possible for many women to get pregnant after 50, it's generally much, much harder and less likely: Women older than 47 account for just .01% of births.
Of course, the children you already have might be teenagers. Many women, like Michelle Obama, who chose to have children in their 30s will reach 50 with teens living in the house, and might be facing all the stress, angst and struggle that comes with seeing a child through adolescence. Up next: College tuition!
2) You're perfectly content to stay home on a Saturday night. In your 20s, you might have felt a certain self-consciousness -- guilt, perhaps, or anxiety -- if your Saturday night was spent in your sweatpants on the couch rather than out being social. These days, whether you're married or single, you might have less energy, but you also know that a weekend night in doesn't spell doom for your social life.
3) Yes, it's hot in here—those are, after all, hot flashes you're having. But that's OK. While menopause can be a slog lasting as long as 12 years, the upside is not having to deal with periods. Ever again. Not to mention PMS, cysts, fibroids, or the aforementioned late-in-life pregnancy. Depression is less common post-menopause. Besides, there's nothing like a hot flash on a cold day.
4) Fifty years in, you know who you are. As Michelle Obama told Parade magazine last summer about reaching 50, "I have never felt more confident in myself, more clear on who I am as a woman." Many people cite their 50s as the best decade, when you know what you want personally and professionally and know -- at least better than you did in your 20s or even 30s, at least -- how to go about getting it if you haven't already.
5) That said, it's not too late to change direction. More and more people over 50 are taking on "encore" careers, reinventing themselves in professions that might more closely align with their passions. Nonprofit group Encore.org, dedicated to helping professionals find their "second act," notes that as many as 9 million people age 44 to 70 are getting paid for work that combines their personal passion with a social purpose.
6) Mentorship isn't over. Though the traditional mentor-mentee relationship puts the older, more experienced worker in the teaching role, just because all your mentors have retired doesn't mean you have no one left to learn from. A recent trend has seen millennials mentoring boomers, teaching them about technology and keeping them current and vital. Some companies have introduced "reverse mentoring" programs designed to pair younger employees with older ones.
7) You sleep less -- and can therefore do more. Studies have found that people need less sleep as they age, leaving them plenty of time to go for a run, work on a project, or do anything else your 20-something cohorts aren't doing while they're dozing an average extra seven hours a week.
8) You can age however gracefully you'd like. If you're going gray, you can flaunt it, and you can be proud of your laugh lines. But if your crow's feet or other signs of 50 years well-lived bother you, there are more options than ever before to do something about it, with fewer stigmas attached. The American Society of Plastic Surgeons reports that minimally invasive facial rejuvenation procedures such as Botox, Juvederm, chemical peels and the like have reached an all-time high. Also growing: eyelid surgery and facelifts.
9) You're your own meteorologist. Medicine has long disputed that achy joints can predict coming rain, but the old joke may have some truth to it. Doctors are coming around to the idea, admitting that those with arthritis, rheumatoid arthritis, fibroid myalgia, or nerve damage in the knees, elbows, and other joints -- more likely, of course, as you grow older -- can indeed feel ambient changes.
10) You're not 60! Enough said, right?
The opinions expressed in this commentary are solely those of Peggy Drexler.