Question

Why did Mao become a Marxist?
I don’t know

Answer 1

Mao envisioned that he could bring revolution to a rural country where the peasants could be the true revolutionaries. By joining the communists the peasants also gained access to more land (as described in your answer ).

Answer 2

Holding that "political power grows out of the barrel of a gun", Maoism emphasizes the "revolutionary struggle of the vast majority of people against the exploiting classes and their state structures", which Mao termed a "people's war