Israel Moiseevich Gelfand
Notices of the AMS February 2013

     "Well, you are doing some homological algebra but we already have Beilinson for that. If you are going to work with me, you have to start from scratch. In medieval times painter’s pupils worked for years just preparing paints for the master. Do you know what a hypergeometric function is? No? Very well, you can work with me on hypergeometric functions."
     After a few days Gelfand changed tactics. He asked me to open the celebrated handbook of Bateman and Erdelyi and point out the formulas I liked. He reacted to my choices quite positively: 
     "Well, you have some taste. Why were you so interested in that abstract nonsense?"