Did Lyndon B. Johnson serve more than 2 full terms?

He mostly served two terms. He finished out Kennedy's term after the assassination, and was then elected to a full term of his own.

He was eligible for a third term, since he hadn't been elected to his first one, but announced that he would not serve or even accept the nomination for another term, mostly under public pressure over his handling of the war in Vietnam.

He increased troop strength from 16,000 to 550,000, and still didn't win the war, which could have been won with a lot fewer than 550,000 soldiers.