John Kerry: Mr. President, I remember Christmas of 1968, sitting on a gunboat in [our italics] Cambodia. I remember what it was like to be shot at by the Vietnamese, Khmer Rouge and Cambodians, and I heard the President of the United States [Richard Nixon] telling the American people I was not there, that our troops were not in Cambodia.
However, Richard Nixon did not become president until January 1969. Furthermore, the Khmer Rouge did not exist in 1968. This Cambodian communist organization was formed in 1970.
Which doesn't mean Senator Kerry doesn't "remember it". Fabricated war stories are the fodder of fools after all.