what should i expect when i get old like the rest of you

A cane or a walker for a birthday present. 

It depends, perhaps, on what your idea of "old" is.

The realities of old age are white-washed and hidden away. Most people don't want to know about it.
And those who choose ignorance are the most likely to suffer from its effects.

I once cared for an 84-year-old who had just lost her husband.
Her constant refrain was, "it's no fun to outlive your friends, dear."
She died two years later of the physical and stress effects of grief.

One of the biggest things oldies most continually deal with is loss.
First, as empty-nesters, they might downsize.
They may lose the family home, their community, and friends may slowly stop visiting and keeping in touch.
Then they may begin to lose their mobility, need a wheelie walker or a wheel-chair. 
Arthritis may prevent them from preparing meals or being able to get dressed in the mornings; they will need a visiting carer.
A high percentage lose their continence (unnecessarily, through lack of exercise and Kegels) - which may isolate them because they are afraid of not getting to a toilet in time, or of smelling foul.
In all these there is a gradual increase of loss of independence, a fear of becoming dependent on others, a loathing of becoming a burden to others.

Some people are far more stoic, independent and resilient.
It is said in disabled communities that everyone will become disabled at some point in their lives; it's only a matter of time.

While this is true for many, it's not absolutely true and certainly not necessary.
How one lives makes a huge difference to the quality of life in the last 20-40-50 years.

The idea of what is old is changing due to advances in plumbing, hygiene, health sciences, medicine and hence the median age to which the majority now live.
And, we normally base this on Western ideas - unwisely forgetting the norms for Africa, India and the rest of the world.

I call 70 the beginning of young-old age, 80 the beginning of middle-old age, and 90 the start of old-old age.
By 90, the majority of well people are likely to be considerably slower, frailer, and in need of some level of assistance,
but there are some who are still running marathon races and in mental games still regularly win against their juniors.

Old age is far more variable and less predictable than infancy and childhood. No two oldies do it in exactly the same way.

I'm 62, have trained and worked in aged care, both in residences and in the community, and looked after my mother at home in her last years.

If a person looks after his or her mental and physical health properly, then the chances are vastly improved; one could live with a healthy mind and body to between 105 and 114, fully able to enjoy the journey.

By "properly" I mean the right way as proven by the latest expert research
(yeah - I know - they seem to change their minds - but it's not as simple as that - there's a difference between what the media and sometimes government publicize, and what's really backed up by valid and evidence based research. One has to go to legitimate sources.
A good one is Dr Michael Moseley - he has the qualifications to research the research.)

The more overweight you are, the more likely you are to suffer from the physical problems of aging. Excess fat is the major cause of diabetes, arterial sclerosis, high blood pressure, heart attack, stroke, and frontal-lobe dementia. It is also a leading cause of fatigue, depression, flat feet, varicose veins, joint pain and joint failure.
Fortunately, weight is not hard to get off and keep off. See "The 5-2 Diet for Beginners".

Alcohol wreaks dreadful havoc. Even the alcoholic who successfully gives it up is likely to suffer chronic long term loss of liver function, heart complications and dementia (Korsakoff's).
Other recreational drugs can also leave permanent physical and mental damage (especially ice), depending on the type of drug and the severity and duration of addiction. One of the effects is that while addicted the addict fails to emotionally mature. Once recovered, the process of maturing can begin again, but the lost years can never be regained.

There are 26 common forms of dementia, of which 7 are very common. In advanced dementia, the body forgets continence, forgets how to swallow, and eventually forgets how to breathe.
The most common is frontal-lobe dementia - a side-effect of low oxygen supply to the brain, caused by arterio-scherosis, a bad heart, too high or too low blood-pressure and the lungs not being able to supply enough oxygen to the blood. This in turn is a side-effect of being overweight. Even a little bit overweight can cause these problems long term.
Some forms of dementia are linked to genes. Inheriting the gene for Alzeimer's does not necessarily mean the person will get it, but if you don't have the gene it's highly unlikely that you will get it.
One can work to prevent (or slow down the progress of) dementia by living a healthy life and regularly practising mental exercises - eg Lumosity, Bridge, Chess, Go, Sudoku, learning a musical instrument, learning a new kind of movement (dance/exercise), keeping socially active and engaged in the community etc.

Something often forgotten and little discussed is oral hygiene. Brushing the teeth and cleaning between them at least twice prevents the gums and jaw bone from becoming infected. When infected, certain chemicals pass along through the blood stream and cause the accumulation of plaque along the blood vessels leading to the heart (the same as fat does.) This greatly affects long term health and mental well-being in old age.

Some problems of old age are inherent in aging itself - hence are unavoidable. The skin becomes drier and less elastic.
(But sunburnt skin and/or a diet high in sugars and highly processed carbs can exaggerate this by 5-10 years.)

From 60, the cartilaginous discs of the spine begin to ossify and shrink. This means that a person shrinks by 2-3" by the age of 70.
If there is any malformation of the posture or spine, this will become exaggerated and can cause pinching of the vertebra and extreme chronic pain. Depending on which vertebra are involved it can also cause sciatica. The bones gradually become more brittle.

Injuries heal more slowly as one ages. It starts with slower healing for bruises and cuts.
In advanced old age, a broken hip can result in permanent disability and a rapid downhill trajectory.
With advanced osteoporosis, the ribs break on a breath, and the person dies by suffocation.

The body's immune system can become less efficient and resilient - making all kinds of cancer more likely. However, cumulative exposure or lack of exposure to carcinogenic chemicals in the environment and food can have a huge impact on this.
Loss of immunity can also lead to being more susceptible to viruses, infections and post viral conditions such as shingles and neuralgia.

Sexual hormones diminish - which means both less sexual desire and less physical capacity for both men and women. Psychological, communication and/or relationship problems can exacerbate this and very often, due to ignorance, the elders themselves do not understand what's going wrong - which can also worsen the problems. But with good understanding, communication and relationship, romance and sexuality can continue in modified (gentler and creative) forms throughout old age between a loving couple.

Many oldies prefer to live single and independent lives, but many others suffer from loneliness and have a very strong need for social and intergenerational connection. A site like this can help a lot.

Old singles are far less likely to find a compatible mate, partly because they tend to be very set in their ways and don't like the changes required to adapt. But oldies in their eighties and nineties can and do sometimes find each other and create successful relationships. My mother's best friend was one such.

Everything I've said above amounts to "how you age depends on how you live" - it's the cumulative result.

That said, time and chance happen to everyone. Some things absolutely cannot be predicted.
But a wise person lives so as to balance the odds in their favour. This post was edited by inky at April 6, 2019 2:34 PM MDT

Well, I was just THINKING about this very thing when I was driving home from work.  I am OLD.  What can I offer people being in this situation.

Age has a LOT of power.    You just have to know that you have it.  All of a sudden you are free.  Free of constraints, meaning I don't have to really listen to anyone if I don't want to because I know what is right. I know how far I can push anything and I know when not to.  This takes years of patience and practice for most people and most people never come to this understanding ever.

If you can think.  If you can wait?  If you can go without anything and wait?  You have all the power you will ever EVER need.

Who says you will? 

Tired at 10pm, can look at pizza and gain 2 pounds, hangovers last 2 days instead of 2 hours. That’s about it. 

Well technology wise I think you can expect a pair of Rocket Pants - all the senior citizens in the future will have Rocket Pants to help them get around. Cheers and happy weekend!