From Rabbi Yisroel Yaakov Klapholz, “Tales of the Baal Shem Tov” (Pe’er HaSefer), Vol. I, sec. 6-7. Rabbi Klapholz translated material from various Chassidic books and oral traditions.
The Baal Shem Tov’s Youth
After a while [the Baal Shem Tov’s] mother also passed away and the boy was left orphaned of both his parents. The townspeople remembered his good father and felt that they owed it to him to educate his son. They paid a teacher to study with him every day, and the boy was successful in his studies. But he had ideas of his own. In those days already, the spirit of G-d rested upon him and he yearned to be alone to pour out his heart to his Creator. He would study a few days with his melamed (teacher) and then would run away to the seclusion of the forest. When the townspeople finally found him alone in the forest, they attributed it to the fact that he was an orphan with no one to care for him, and they would return him to his teacher. (Shivchei Baal Shem Tov)
"I was five years old," the Baal Shem Tov told later on, "when I was orphaned from both my parents. My father's last words to me were, ‘Yisroelik, never fear anything, just fear the Almighty himself.’
"In accordance with my father's words, I yearned greatly to go out to the fields and forests that were on the outskirts of our town. When I had finished my lessons, I used to go out to the fields and review by heart everything I had learned. I often slept over night out in the open. This went on for about two years.
"Once when I came to the forest after having davened at sunrise, I heard a voice. I followed the sound until I discovered a Jew, wrapped in his talis and tefillin, davening with such fervor as I had never seen before. I hid behind the trees and listened with pleasure to his inspiring prayers. ‘This must surely be one of the thirty-six hidden tzaddikim that are in each generation,’ I thought to myself. When he had finished, he removed his talis and tefillin and began saying Tehillim (psalms) with infinite sweetness.
"He sat there for a long time and studied with great enjoyment. When he had finished, he gathered all his seforim and his talis and tefillin and put them into his knapsack. As he started on his way, knapsack on his shoulder and walking stick in hand, I emerged from my hiding place and went towards him.
"When he discerned me he asked, 'What is such a little boy doing alone in this great forest?’
"I told him my father's last words to me, concluding, 'And so I am not afraid to be in the forest. I love it here because here there are no liars and no proud and haughty people.'
"When the old man heard that I was the son of Reb Eliezer he took a Gemora Pesochim out of his knapsack and began learning with me. From that time on, I stayed with this Jew and wandered about, I know not where. We passed through cities and villages, towns and settlements. I did not know his name. Each day he would study with me, and I never saw him, in all this time, accept charity from anyone, though he provided for me all along. We lived thus for about three years.
"One day we came to a small settlement. He brought me to a house in the forest nearby and said to me, 'I will leave you here with my friend, Reb Meir,' and he left.
"I stayed in Reb Meir's house for four years. He studied Torah intensively with me during that time. Every day we would go to the settlement to daven with the townspeople. None of them realized how great he was. They thought of him simply as Reb Meir, the laborer.
"While there, I learned of all the unknown tzaddikim who wished their identity to be kept secret and of the saintly Reb Adam Baal Shem. I joined a group of them and wandered together with them from city to city and settlement to settlement and served them as best I could. At the ago, of sixteen I had already acquired an extensive knowledge of Kabbalah. I would pray from time to time according to the Arizal's arrangement of the prayers, using certain holy names that Reb Chaim the "Nistor (Hidden)" had taught me." (Sifrei Chabad)