Anything cool happen on your birthday?

Yes, for the people of Vietnam the year 1975 was an interesting year. I am not sure of the source you used - but my sources read that on April 30, 1975, the people of Vietnam finally unified their country after two decades of division and war (against the United States and its allies) and the war was brought to an end. After fighting for 30 years against the French and then the Americans, when peace finally came to Vietnam it was "cool."