In his teens he walked 1 000-ri from Badaogou in China to Mangyongdae, his birthplace in Korea, all alone to learn about his homeland and fellow countrymen.

Braving severe snowstorm, he had to go over steep and craggy, uninhabited mountains and hills where fierce wild animals were prowling about.

In his reminiscences "With the Century", Kim Il Sung wrote, recalling the days:

"I suffered a lot during the journey. I really had a hard time of it while crossing the Jik Pass, Kae Pass (Myongmun Pass) and the like. It took me a whole day to cross the passes in Mt. Oga. When I had crossed one pass another would appear. It seemed there was no end."

In the course of journey the profound meaning of what his father Kim Hyong Jik had said to him on his departure about learning about Korea came home to him.

Seeing people groaning under the colonial rule of the Japanese imperialists, he made determination to annihilate the Japanese imperialists who reduced Korea to be a living hell.

He spent two years back in the homeland, during which he learned and experienced a lot of things.

The popular masses were shedding their blood in resistance to the Japanese imperialists. Seeing them he felt an undaunted sense of national dignity and unbreakable spirit of independence.

From that time he believed that he could liberate the country if he organized their efforts properly.

Because he went to Korea while others went abroad, he could deeply learn about his homeland and the Korean people and got a good understanding about the enemy.

Years later, he started an anti-Japanese armed struggle to lead Korea to liberation.