Nobody has brought up the visual part of aging, which for ME has proven to be as big a frustration as anything. It can be downright debilitating in flat light. It gets more challenging every year. I am still progressing as a skier since I learned as an adult, but I also ski with some fabulous skiers--instructors, PSIA examiners/L3s/former racers, and all of them are over 50, many over 60, and every one of them has been slowed down by their vision as much as anything. I also ski with a former world-pro mogul skier who's in his 60s who doesn't spend much time in the moguls anymore. He's got a lot of aches and pains from those days that make it pretty painful. That being said, he is still a fantastic skier who is out there having fun. My unscientific observation is that woman are more affected by the decline in vision than men, as it relates to skiing at least.
Aging can be rather depressing at times, for sure. The mental aspect of learning to accept the inevitable fact that your body is slowing down, your reflexes are slowing down, your vision degrades, is an integral part of a good mindset of gratitude as it all occurs. I mean, you're not the life-long couch potato who has debilitating arthritis simply due to being overweight, who as they age lose their ability to balance, their ability to even walk down the street, so pat yourself on the back for that. Skiing is good exercise for our balance skills, our reaction time, and that's all very important for quality of life as we get older. Mountain biking provides the same benefits, in addition to being a kick ass cardio workout, too.
So yes, we can all commiserate with getting older (I'm still a "young pup" at almost 52) and that it's pretty frustrating at times as our bodies flip us the bird when we try to do the things we used to do with ease, but we are still in a better place than many who are half or even 1/4 of our age, which should be celebrated! Menopause makes it happen all within a year for women, too. It's like this light switch turns off in so many ways. We also must remember that 100 years ago, many of us would literally be working ourselves to death.