You are young in proportion to your flexibility. Watch a small child – so soft, tender, and flexible. As you grow old everything becomes tight, hard, inflexible. But you can remain absolutely young to the very moment of your death if you remain flexible.

When you are happy you expand. When you are afraid you shrink, you hide in your shell, because if you go out there may be some danger. You shrink in every way – in love, in relationships, in meditation, in every way. You become a turtle and you shrink inside.

If you remain in fear continuously, as many people live, by and by the elasticity of your energy is lost. You become a stagnant pool, you are no longer flowing, no longer a river. Then you feel more and more dead every day.

But fear has a natural use. When the house is on fire you have to escape. Don’t try being unafraid there or you will be a fool! One should also remain capable of shrinking, because there are moments when one needs to stop the flow. One should be able to go out, to come in, to go out, to come in. this is flexibility: expansion, shrinking, expansion, shrinking. It is just like breathing. People who are very afraid don’t breathe deeply, because even that expansion brings fear. Their chest will shrink; they will have a sunken chest.

So try to find out ways to make your energy move. Sometimes even anger is good. At least it moves your energy. If you have to choose between fear and anger, chose anger. But don’t go to the other extreme. Expansion is good, but you should not become addicted to it. The real thing to remember is flexibility: the capacity to move from one end to another.

Everyday Osho — 365 Daily meditations for the here and now by Osho

That which is old grows stiff and then decays. That which is young is pliant and soft. Therefore, those who follow Tao follow the way of softness in order to avoid death.

There are many ways to apply this ideal. You could interpret it literally and so try to maintain whatever limberness you have. Or you might understand it to mean that to harden your position toward others inevitably leads to your downfall: the dogmatic — the stiff — are often the first to be undermined. — Deng Ming-Dao, Everyday Tao

When young, things are soft.
When old, things are brittle.

Stretching — both literally and metaphorically — is a necessary part of life.

Physically, a good program of stretching emphasizes all parts of the body. You loosen the joints and tendons first, so that the subsequent movements will not hurt. Then methodically stretch the body, beginning with the larger muscle groups such as the legs, and back, and proceed to finder and smaller parts like the fingers. Coordinate stretching with breathing, use long and gentle stretches rather than bouncing ones. When you stretch in one direction, always be sure to stretch in the opposite direction as well. If you follow this procedure, your flexibility will undoubtedly increase.

Metaphorical stretching leads to expansion and flexibility in personal growth. A young plant is tender and pliant. An older one is stiff, woody, and vulnerable to breaking. Softness is thus equated with life, hardness with death. The more flexible you are, the greater your mental and physical health.

Deng Ming-Dao, 365 Tao

Nothing in the world is more flexible and yielding than water. Yet when it attacks the firm and the strong, none can withstand it, because they have no way to change it. So the flexible overcome the adamant, the yielding overcome the forceful. Everyone knows this, but no one can do it. — Lao Tzu, Tao Te Ching

A man is born gentle and weak.
At his death he is hard and stiff.
Green plants are tender and filled with sap.
At their death they are withered and dry.
Therefore the stiff and unbending is the disciple of death.
The gentle and yielding is the disciple of life.
Thus an army without flexibility never wins a battle.
A tree that is unbending is easily broken.
The hard and strong will fall.
The soft and weak will overcome.

Tao Te Ching, 76