Why does Nkrumah say it is not surprising that tension and unrest occur in colonies?

Kwame Nkrumah says that it is not surprising that tension and unrest occur in the colonies due to the oppression exerted by the colonial powers against the dominated peoples. This phrase is congruent to his anticolonialist and independence vision, for which Nkrumah fought in his native Ghana.

Explanation:

Kwame Nkrumah was Ghana's first President. He is regarded as one of the most important figures in the development of African Nationalism.

He was born in Nkroful, in what was then the British colony of the Gold Coast. In 1935 he traveled to the United States to study, graduating at Lincoln University, Pennsylvania.

In 1947 he was invited to serve as secretary to a commission under Joseph B. Danquah which was exploring the possibility of Gold Coast independence. He returned to the country in December of that year. In 1948 he was imprisoned by the British authorities. After his release, he worked his way around the country campaigning for self-government. He was imprisoned again in 1950, this time for three years. Under international pressure, Britain agreed to hold an election in February 1951, and Nkrumah's party won a sweeping victory. He was released, and asked to form a government. A year later, he was named Prime Minister. On March 6, 1957, Nkrumah declared Ghana an independent country. In 1960 Ghana became a republic, and Nkrumah became President.

you really can't answer this on your own?