This is a story of the Buddha as told by Ajahn Chah that I really like. He describes how in a former life, as King Mahajanaka, the Buddha learned of the dhamma from a mango tree...
The Buddha understood the uncertain nature of things. He observed the phenomenon of fruit in the wind and reflected upon the monks and novices who were his disciples. He found that they, too, were essentially of the same nature - uncertain! How could it be otherwise? This is just the way of all things.
Thus, for one who is practicing with awareness, it isn't necessary to have someone to advise and teach all that much to be able to see and understand. An example is the case of the Buddha who, in a previous life, was King Mahajanaka. He didn't need to study very much. All he had to do was observe a mango tree.
One day, while visiting a park with his retinue of ministers, from atop his elephant, he spied some mango tees heavily laden with ripe fruit. Not being able to stop at that time, he determined in his mind to return later to partake of some. Little did he know, however, that his ministers, coming along behind, would greedily gather them all up; that they would use poles to knock them down, beating and breaking the branches and tearing and scattering the leaves. Returning in the evening to the mango grove, the king, already imagining in his mind the delicious taste of the mangoes, suddenly discovered that they were all gone, completely finished! And not only that, but the branches and leaves had been thoroughly thrashed and scattered.
The king, quite disappointed and upset, then noticed another mango tree nearby with its leaves and branches still intact. He wondered why. He then realized it was because that tree had no fruit. If a tree has no fruit nobody disturbs it and so its leaves and branches are not damaged. This lesson kept him absorbed in thought all the way back to the palace: ''It is unpleasant, troublesome and difficult to be a king. It requires constant concern for all his subjects. What if there are attempts to attack, plunder and seize parts of his kingdom?''
He could not rest peacefully; even in his sleep he was disturbed by dreams. He saw in his mind, once again, the mango tree without fruit and its undamaged leaves and branches. ''If we become similar to that mango tree'', he thought, ''our ''leaves'' and ''branches'', too, would not be damaged.'' In his chamber he sat and meditated. Finally, he decided to ordain as a monk, having been inspired by this lesson of the mango tree. He compared himself to that mango tree and concluded that if one didn't become involved in the ways of the world, one would be truly independent, free from worries or difficulties. The mind would be untroubled.
Reflecting thus, he ordained. From then on, wherever he went, when asked who his teacher was, he would answer, ''A mango tree''. He didn't need to receive teaching all that much. A mango tree was the cause of his Awakening to the Opanayiko-Dhamma, the teaching leading inwards. And with this Awakening, he became a monk, one who has few concerns, is content with little, and who delights in solitude. His royal status given up, his mind was finally at peace.
In this story the Buddha was a Bodhisatta who developed his practice in this way continuously. Like the Buddha as King Mahajanaka, we, too, should look around us and be observant because everything in the world is ready to teach us. With even a little intuitive wisdom, we will then be able to see clearly through the ways of the world. We will come to understand that everything in the world is a teacher. Trees and vines, for example, can all reveal the true nature of reality. With wisdom there is no need to question anyone, no need to study. We can learn from nature enough to be enlightened, as in the story of King Mahajanaka, because everything follows the way of truth. It does not diverge from truth.
If we have awareness and understanding, if we study with wisdom and mindfulness, we will see Dhamma as reality. Thus, we sill see people as constantly being born, changing and finally passing away. Everyone is subject to the cycle of birth and death, and because of this, everyone in the universe is as One being. Thus, seeing one person clearly and distinctly is the same as seeing every person in the world.
In the same way, everything is Dhamma. Not only the things we see with our physical eye, but also the things we see in our minds. A thought arises, then changes and passes away. It is ''nāma dhamma'', simply a mental impression that arises and passes away. This is the real nature of the mind. Altogether, this is the noble truth of Dhamma. If one doesn't look and observe in this way, one doesn't really see! If one does see, one will have the wisdom to listen to the Dhamma as proclaimed by the Buddha.
This story fits well with my experiences so far, in that while I have learned much from advanced practitioners, teachers, life events, books, nature and spiritual friends I have yet to cultivate a one-to-one teacher/student relationship with a Buddhist teacher in this life. I am not adverse to the idea, it just hasn't happened yet. Still, i feel i have constantly learned things from life, and the natural world all around us. I feel like dhamma lessons are being thrown my way constantly...
I would think that even with a teacher this is often true, no?