Age impacts everyone. Being 75 and in good health can be a most delightful time in ones life. Mentally one does experience deterioration of brain cells, but with brain exercises and good nutrition the brain can fully function at that age. The body is also in need of a healthy lifestyle. Good nutrition, exercise, and rest, along with stress management can impact the quality of ones life and alleviate the general minor aches and pains with stiff joints and soreness that accompany normal aging. The skin is an outward factor that wrinkles and spots with age, but with the extensive line of beauty and skin care practices many people can reduce these effects ! Aging happens to everybody but can be a graceful experience if a healthy lifestyle is practiced!
I am going to answer you from two perspectives: my aunt who is very active and 80+, and my mother-in-law who is more frail and living in a residential community.
My Aunt Sara lives on her farm in rural Tennessee. She was an activist in her younger days and went out on strike for the ILGWU in the 1940s. She was a factory worker in the garment industry all of her adult life. And, she ran a dairy farm very nearly single-handedly.
After she retired from her "job" she continued to keep and raise cattle for beef, honey bees and garden. She began to lose friends at about the time of her retirement. I think the first year of her retirement, she went to about 10 funerals of age-mates. This is when life gets hard for persons who are getting older. The people with whom they share memories begin to die off.
She has outlived her husband and two siblings. She continues to drive, garden and rent her farm out to a cattleman. Her health is good, but she has aches and pains. Her philosophy is, "Keep moving!" Each day is a new day, and she looks forward to each new day.
My mother-in-law is 80+ years old as well. She lives in a retirement home in sub-urban Alabama. During her younger days, she was a Sergeant in the Army WACS. Again, she was an activist of sorts for women in that she joined the Army when everyone else was staying home, wrapping bandages, and going to work in factories to help in the war effort. Being in the Army was her glory.
After the war was over, my mother-in-law was a stay-at-home mom. That meant she went to bridge clubs, women's society meetings, and generally made meals and went to PTA meetings with her school age children. I am thinking that this life was quite a let-down from her high point in the Army.
My Mom-in-Law has asthma and other aches and pains. She no longer drives or has the entertainment schedule that she used to. Most of her "friends" are dead, and her Army buddy has Alzheimers Disease. She has one living sibling out of 6. So the pals she made her memories with are gone. She feels lonely and isolated in the retirement home because there are no kids there. And, she is a FAMILY person. My mom-in-law sometimes wishes for death because she is so terribly lonely and frail. I do not think she wakes up eager for each new day. Maybe this is depression, maybe it's just that she's old and tired.
So, to sum up, being 75 and up is different for different people. If you are in good health, you experience the lonliness of your friends and spouse dying before you. If you are in frail health, you experience loss of ability and freedom as your health declines gradually day-by-day. Either way, with age comes loss.
Some people 70 is the new 50. And, I can see that. Many 75+ folks choose that time in their lives to travel and have their big adventures that they did not have when they were working and raising families.