It happened on the birthday of Chairman Kim Jong Il in Juche 52(1963).
That day, his university mates asked him to celebrate his birthday together with them.
Saying that he was very thankful for their sincerity and comradely love, the Chairman told them in a low tone that he could not celebrate his birthday.
His mates looked up at him with an ardent passion that he would reconsider his decision while making no secret of their unsatisfied feelings.
After thinking for a while, he said that President Kim Il Sung had never celebrated his birthday so far, though he had devoted his lifetime to the country and people. He could not celebrate his birthday as the President had spared no pains for national prosperity and people`s happiness, he noted.
He added that they should think only one thing how they could remove the apprehensions of the President and meet his convenience even for a moment and how they could repay the favour shown by him more satisfactorily by studying hard and taking an active part in an organizational work, and the true happiness of a revolutionary soldier lies in lightening his labour.
His instruction on the true happiness of a revolutionary soldier gave them a great shock.