Your nails are a product of evolution, they evolved from claws.
We've been told that we have flat nails to:
• Protect our fingertips,
• Make it easier to grasp small objects,
• ...

Well, now we know the answer;

Just like hooves, fingernails evolved from the claws of reptiles.
Around sixty-five million years ago, a reduction in the thickness of the deep layer of the claw led to the development of nails in the earliest primates.
Primates are not the only animals to possess flat nails; some marsupials do as well.
This is a good example of parallel evolution; which is the development of similarities in separate lineages.
This demonstrates that flat nails are an important evolutionary goal.

There is an intermediate evolutionary phase between claws and nails; it is called the "toilet-claw".
Early primates possessed these claws on the second digit of their hands and feet.
Just like nails, toilet claws are made of keratin.
Their shape is similar to claws, but their tips are less pointed.
Prosimian primates still have toilet claws nowadays, while the nails of a few South American monkey species have reversed back to claws.

We don't think of our nails as sensitive, since we trim them painlessly.
It's true that the nail plate, made of tough, translucent keratin, cannot feel anything.
However, it rests on the nail bed, a portion of skin directly beneath the nail.
The nail's bed is, as you might expect, packed with nerve endings and blood vessels, giving the nails their pinkish color.
Sensations received by the nail itself are amplified by this system.

Nails grow about ⅛ of an inch (3 mm) a month.
Your nails can be too short, or too long, to adequately perform your grooming activities.

The nail barely exceeds the top of the finger, when seen from underneath.

When the nail reaches ¼ inch above the fingertip, it starts bending under the pressure.

You end up keeping your nails within a grooming range.

• When your nails are too short; the sensory signals from the nail and the fingertip become confused.
Worse, the nail doesn't extend far enough to secure any hold on the folds, and it cannot reach the bottom of deep crevices and pits.
• Too long; nails become brittle and lose some rigidity.
They become curved and crooked.

Trimming your nails with scissors, or a clipper, is essential if you want your grooming to be productive.
You don't want to cut them too short.
They should be brought back to the briefest of the grooming range.
This is a time to be very attentive.
It's so easy to go crookedly.
Be especially careful not to create dents.

It's the corners of your nails that you will be using most for grooming.
For this reason, I recommend not trying to give your nails a rounded style.
• Cut or clip each nail with only a slight curve.

This operation leaves the corners of the nails too sharp.
• In a second operation, give a slight finishing trim on both sides of the nail.

Trimming the corners of your nails allows the nail to flatten, and makes your grooming less hazardous.
• The third step involves using a nail file to smooth the sharp edges, and perfect your work.

Some fingers are used much more than others while carrying out grooming operations.
You might decide to keep some nails longer than others as your grooming technique develops, or for personal reasons.
Ideally, the length of the four fingernails on both hands should fall within the grooming range.
Your thumbs are optional, since little grooming is done with them.

You should be using your writing hand, whether right or left, to perform most of your grooming.
Throughout your life, you've developed a great deal of specialization for each hand.
One of them has become your preferred hand for working with precision and delicacy.
Writing usually tops the list of such activities, with its need for precision and detail, much like grooming.

When you dig or cut deep into your own skin, you want to use your most agile and sensitive finger.
Grooming is very precise and tricky work, where any mistake can provoke immediate pain and possibly injury.
The finger to use is the index finger of your writing hand.
It is called that way because it was used to flip index cards.
Now, I'm offended by such an artificial name, and I prefer naming it after its natural usage; grooming.

The nail at the end of your grooming finger is particularly important.
Avoid using that nail in any damaging way.

In my case, the fingers on my writing hand are more sensitive than those on my other hand.
Also, my fingers decrease in sensitivity as they get farther from the index.

This creates a finger sensitivity map.
You can use fingers with less responsiveness on tasks that demand less exactness.

Your nails, like many other body parts, reflect your health.
Be on the lookout for any abnormalities.
Changes in color, depressions and ridges, curvature, brittleness, ... could be signs of health problems.
With grooming, your nails become an essential element of your well-being and appearance, as well as being indispensable in your everyday life.
Take pride in them, wear gloves when doing risky or damaging work.

You can usually clean the top side of your nails easily with water in a few seconds.
Their smooth and hard texture makes them easy to wash.
It's the underside of the nail that poses a problem.
Before growing longer than your fingertip, this surface was attached to the nail's bed.
It's porous, and it's difficult to remove dirt from it.

• To clean your nails; soap and water, with the help of your other nails, do a fine job.
• Try not to go too deep when going beneath the nail.
This area is easily hurt; it's normal that you can't reach the bottom.
• Only use hard objects, like the tip of a nail file, when necessary.

The nail on the finger you use for grooming gets dirty quite fast.
In reality, the space between the blade and the flesh gets filled with epidermal cells that you rake off your skin.
The color of the cells that accumulate depends on your natural skin tone, and on how tanned you are.
So, their dark coloration is no sign of uncleanness.
The entire area beneath the nail can fill up in less than two minutes of grooming.
The presence of litter in the gap can reduce the sensations you receive from the nail.
Since it wouldn't make sense to wash your hands every few minutes, it's best to keep a piece of facial tissue close by.

I have not experienced any contact infections, spread through direct skin-to-skin contact, since I began grooming my own skin in 2002.
So, I would assume that grooming your own skin doesn't transmit infections.
You're safe as long as you only groom yourself.
Things are very different if you groom someone else.
Even if you wash your hands frequently, the risk of transmission remains.

Don't apply any nail polish, or try to embellish your nails in any manner.
You wouldn't want to groom yourself with questionable products on your nails.
Stop thinking of nails as useless decorations.
They are naturally beautiful, without adding anything, mostly when their length is in the grooming range.

Many people have acquired uncontrolled behaviors with this part of their body.
Nail biting, picking at peeling skin, and auto-mutilation are common practices.
Continuing or stopping these activities says a lot about the control you have over yourself.
Take responsibility for your actions.

Though I advocate removing chapped or flaking skin in most areas of the body, the skin at the junction of the nail and the skin requires special care.
If you pull on the hanging peelings, you may rip the skin and hurt yourself.
Instead, cut them clean with a clipper, and groom the area very delicately.

I've had a hard time getting used to having long nails.
They make simple things, such as picking up a coin, more difficult.
Typing on a keyboard becomes an adventure.
We need a new line of instruments made for long nail bearers.
But, in any event, humans will have to adapt to life with long nails.
It's part of being primates.

Your nails are formidable tools for grooming.
Sensitive yet tough, they can be driven firmly into the skin without harming it.
Their shape and dimensions are just right for the task they were designed for.
Humans are branded as a tool-making race, but these tools have been designed by God; so they feel and grow.