how to flatter

Some one asked me, "What do you think about the talk?"

I said, "It is great. The talk is easy for a broad audience to understand, but it is actually very deep."

That person continued, "The talk looks easy on the surface, but smart guys can still appreciate it."

I answered in a wrongful way, "Well, I have listened to it many times."

My answer is not very smart because I assume I am the smart one. A better answer may be "Yes, the question you asked is really right to the point." Haha, I am still slow on the spot.