Qin Shihuang, for example, would not have a glorious history without the division of the Warring States period.
Kangxi, if there was no corruption in the late Ming Dynasty, there would be no Manchu Dynasty. If Shunzhi didn't die so early, there would be no young Kangxi to capture Ao Bai, and there would be no great cause of cutting Francisco for three transgressions and five times. There have been no emperors since ancient times.
Gandhi, if there were no British colonization, Indians would not seek independence. Without independence, there would be no Gandhi. Probably selling vegetables there.
Washington, if it were not for British colonization, Americans would not resist and there would be no Washington. Actually, it's similar to Gandhi.
In short, it is the times that make heroes. If Mao Zedong was born in the realistic China, he may be mediocre all his life, and even if he achieves something, he will never be a great man of the century.