Natasha,
I never heard a Postal Clerk called a Math and Science person before. Although, Walter could have been a Physicist, a Mathematician, an Engineer. or anything else Math or Science related. In actuality, he really is one of the smartest people I know, however, I am married to the smartest. Can't let his head get too big you know. Walter began working for the Post Office while going to College and stayed after he graduated. If you ever get to look at his log book, you will see that he is a frustrated Engineer or Statistician. Lots of statistical details in there. As an Engineer myself, I totally understand, but dealing with numbers daily allows me to have normal looking log book. However, if I dived as much as Walter, I may have the same interest in the details.