Here's the truth:
I don't feel any different today than when I was in my twenties. Physically and in every other way I feel the same. Okay, except that I can't read without my readers. The face I see in the mirror has some lines I'd remove if I could, but they don't bother me enough to consider anything drastic. My hair is pretty much all gray but you can't tell thanks to my stylist. The thing that keeps me coloring it is when I pass a slow driver the first thing I do is check to see if they have gray hair or if they are on the phone. Or both.
My advice: Keep moving, do some yoga, and get outside. Wear sunscreen. Stretch. I knew early on I'd never be a runner, but I walk most days. Your body simply cannot be healthy if it's sedentary.
This is the smartest I've ever been. I'm a genius compared to my 25 year old self. Wherever you are in life this is the smartest you've ever been too! I would never be willing to turn back the clock unless I could take my 50 year old brain with me.
My advice: Get a library card. Read. Everything. Read history, political science, self help books, books on other religions, spirituality, biographies (!). Go back and read all the classics you skipped in school. Read how-to-books, on gardening and cooking and decorating. Read Science books. If you want to know about something complex, like physics, start with a book written on a 5th or 6th grade level and then work your way up. Read travel essays and books about explorations and expeditions. Do not limit yourself or tell yourself that there is anything you can't understand. The great minds of every field have written down what they learned, don't waste that knowledge.
I know how fortunate I am. Every day I'm more aware of not only fortunate but privileged I am. A real calamity in my life is if I run out of coffee. I have never had to worry about my next meal or where I would sleep. I have never faced a serious illness. My children have never been seriously ill. I turn on the tap and clean water comes out. As I write this the heat just kicked on. On a global scale most of us are incredibly wealthy.
My advice: Count your blessings. It's cliche, I know. Do it anyway.
I'm wiser. I'd be less than truthful if I said that some of that gaining wisdom up to this point wasn't a painful process. Coming to terms with truth is hard. Letting old ideas go is uncomfortable. Having an open mind is a challenge. Admitting you were wrong can make you squirm.
You can read about what I've learned in the past five years here.
My advice: Open your mind to the possibility that you may have ideas that are wrong. That you may be uninformed, or misinformed. Don't be so sure you are right. Make sure you know lots of people who have different ideas about politics and faith than you do. Assume that people who have different opinions than you have come to those conclusions, not because they are evil, but because they have had different life experiences. Make allowances for people's weaknesses. Be kind and generous and forgiving.
I don't compare myself anymore. "Comparison is the thief of joy." That may be the truest statement ever. Someone is always younger, prettier, smarter, richer, funnier, more well read...and on and on. Get over that and only compare where you are now to your past self. You'll be encouraged if you just keep moving forward in your own life and mark your own progress.
My advice: Pray for wisdom. Count your blessings. Don't compare your inside to someone else's outside, but don't compare your outside to theirs either. Focus on what makes you happy. If you are feeling sorry for yourself, volunteer someplace.
I'm excited about the future. There's so much more to learn and do. I'm constantly encouraged by some of the people I know and volunteer with who are decades older than me. They still travel and work hard to make a difference in their communities. They are interesting people and they are interested in the world. They are always excited about learning something new and sharing their experiences with others.
My advice: Never stop being interested in the world and surround yourself with people older than you who are aging in a way that you find encouraging.
You can read more about what I've learned about "living young" here.