The Vedic culture is very scientific and is a precise science; science of the entire creation and the science of being as a microcosm of the macrocosm, which is the physically manifested creation. It very clearly lays down the path and also how to walk on it and provides tools and techniques such that the secrets of the creation are revealed to you; so that the final merger happens with full consciousness in a disease-free body… at will.
The Success rate is very low
The reason why there are so many seekers and very few who achieve success is simple. Those who achieve success have three things in common – a Guru who has the traits of five yamas of ashtang yog, priority to the subject over other things in life and, regular practice along with service and charity. The above three things are tied into the framework of four ashrams – brahmcharya, grihasta, vaanprasth and sanyaas. Each of these ashrams naturally flows into the next, it is not forced, the right practice of yog under a guru ensures this
Renunciation is a Myth
I will give a little insight into the vaanprastha stage for a yog-guru. Normally people think that it is renunciation, but there is no such thing as renouncing the world. One goes through it like a ship goes through the ocean, it is on the water and crosses the water, but is not in it and so it does not sink. Vaanprastha simply means to begin the process of limiting your interactions with the mundane aspects of life, and with people whose priority is not yog. In vaanprastha, teachings continue and interactions with sadhaks go on. It can be called that the ship is in the middle of the ocean and is moving towards its finality. Those on the ship are limited as only those who trust the ship fully are allowed. How long you have known the ship (guru) is of no consequence, your desire and other prerequisites are important.
Having collected the force within for the onward journey in the years of brahmcharya and having gone through the experiences of a worldly life as a grihasta, a being takes a step back from the physical world as he enters vaanprastha, because to reach the final destination, all this has to be left behind. For a rocket to break the pull out of gravity, it has to leave its excess weight. Leaving does not imply running away, the thought of the physical has to go.

Yogah Chitt Vritti Nirodh
Let me explain this with the help of the example of a rishi who left his family and house to do dhyan in Himalayas. The rishi followed a niyam of offering milk to the shivling every day. As he went to the Himalayas, commoners from nearby villages would bring him milk and he would carry on with his practice. Once no one came to give the milk. In the absence of milk, the rishi offered water to the shivling. However, it soon became a common occurring, the villagers would often forget to bring him milk. The rishi then decided to keep a cow so that he does not have to depend on the villagers. When he went to village to get the cow, the villagers advised him to also take a lady with him to take care of the cow as he would be in dhyan for long hours. The rishi agreed. Five years passed. The villagers then asked the rishi to marry the lady since no one else would take her. The rishi agreed. He married her and they had a family. So, whatever he had left, was created back again for him because of his one thought. That is why it is said, ‘yogah chitt vritti nirodh‘. One needs to silence the modifications of the mind to access what lies beyond the five senses. Vaanprastha is preparatory stage, which further leads to sanyas.
Every Action has an Equal and Opposite Reaction
After a stage a yogi needs to limit his/her interactions with normal people. There is a story in the Mandukya Upanishad about a group of rishis who used to live in Himalayas. One day these rishis suddenly realised that their bodies had started ageing. (A Yogi’s body does not age. He/she leaves the body in full consciousness and strength, being aware of where he/she is going.) The rishis then had a discussion on the possible reasons for ageing. They realised that this happened as they left their Himalayan abode to settle in the villages resulting in increased interactions with normal people. When you have interaction with normal people, there is intermingling of thoughts and energy patterns. And then the body begins to exhibit the symptoms of a normal human being – eat, drink and make merry. Vedic masters say, and modern science agrees that every action has an equal and opposite reaction. When you resort to pleasures of the five senses, as an equal and opposite reaction, the body begins to age. This ageing has to be held back to garner the energy to make the final journey beyond the five senses and also take the deserving shishyas beyond. So during the phase of vanprastha, you limit your interactions otherwise the body ages very fast.
Traits of a GURU
Now let me give you the traits of a guru – a Guru is someone who does not charge you a fee because someone who is him/herself tied in maya cannot release you, he/she exudes the glow and attraction associated with yog, diseases disappear in his/her presence, whatever he/she says happens, and he/she is sthir in the five yams. So my suggestion is look for a guru, give the subject priority and you will be called on board on this beautiful journey called yog.