Since I'm generally an optimist (unless it comes to politics, although, occasionally I am surprised by good things happening), I would argue that there are lots of upsides of getting older.
For one thing, when I was younger, I never liked other people being the boss of me. While I was a fairly obedient child, I always itched to be an adult and not have to live by someone else's rules. Being an adult-- especially one who is self-employed--gives you a fair amount of freedom that you just don't enjoy as a kid.
Also, as trite as it is, in your teens and 20s you're still evolving into who you are. Yes, it's an ongoing process (I do live in San Francisco--of course I believe that life is a journey!) but in my case, my 20s were a little too drifty. My 30s have been a much more confident and happy decade in every sense. I believe my 40s will be even better, full of more professional success, time with those I love, and world travel.
However, I'm not gonna lie to you: aging pretty much sucks from a physical standpoint. The metabolism slows. I have to work harder just to stay the same size. Tiny lines appear and don't leave. I buy things with "anti-aging" in the name. I've yet to get a grey hair, but I'm sure it won't be long. And, since I hope to live a long and happy life, occasionally I have to forego my decadent nature in favor of moderation. You can't stop time but you can try and slow the clock with some good habits.
Enter chicken kebabs with nectarine salsa, courtesy of Cooking Light. I pretty much followed the recipe, which you can find here, with minor exceptions--I don't go for bottled garlic, and I used a mix of white and dark meat. But I have to say, as skeptical as I was (I'm hard-wired to scoff at healthy recipes), this was really delicious. The marinade would also be good on shrimp or pork (here I go, tweaking the recipe away from healthy) and the salsa would be fantastic with either of those things, or on grilled fish. And since the kebabs are broiled not grilled, they were hassle-free.
The dish was also colorful beyond belief and fun to eat (skewers always seem like a party), almost making me forget about eating healthy and hurtling toward death.