A lot of Gedolim stories bother me. What is the point of this story? We all know that the Rogochover was an incredible genius. We don’t need more and more stories to prove just how much of a genius he is. A Godol is not measured by the extent to which Hashem gave him mental capabilities. (Not to mention the fact that the Rogocover answered most letters by listing off Mar’eh Mekomos that discuss and will answer the question.)
The lesson to be learned from this story should be that the Rogochover took over 2 hours out of his incredibly busy schedule to personally answer these letters. I’m sure some of them were easy questions and he could have had a Talmid sift through them to weed out the simple ones or he could have not gotten to some due to time constraints. The lesson here is that he spent over 2 hours (immediately after not being able to write anything down for 25) answering questions from all over the world just because people mailed them to him.