I once ordered a copy of Introduction to Algorithms (CLRS) on Amazon. I had been a TA for Thomas Cormen at the time, and wanted the author's signature. He took

I once ordered a copy of Introduction to Algorithms (CLRS) on Amazon. I had been a TA for Thomas Cormen at the time, and wanted the author's signature. He took one look at it, compared it to the copies he had in his office and said, "This is a counterfeit copy. Where did you get this?" The embarrassment haunts me to this day.