The Vilna Gaon’s diligence in Torah study was legendary. His days were spent in his room, delving into the depths of the Torah with every ounce of strength that he possessed.On one occasion, the Gaon’s sister arrived from a distant land in order to pay him a visit. This was by no means a minor event, as the two had not seen each other for some fifty years !The Gaon went out to greet his sister and, as the halachah dictates, recited the blessing that is said upon seeing an acquaintance that one has not seen for a long time – ”Blessed are You, Hashem… Who resuscitates the dead.”After concluding the blessing, the Gaon said to his sister: ”My dear sister. I know that we have not seen one another for quite some time. However, when I leave this world and am called before the Heavenly Tribune, I will be asked to give an accounting for every single second of my life. Each moment of time will be scrutinized and judged on whether or not it was utilized studying Torah and performing Hashem’s mitzvos. How, then, can I waste away the precious time that I have been allotted, by engaging in trivial conversations?””I therefore beg your forgiveness, but I must return to my room and resume my Torah study.”
From Shirat Devorah, here.