Why Did Jesus Originally Say to 'Tell No One' That He is the Messiah?

A listener named Kathy asks Father Dave about a recent reading at Mass. "A question came to me on Sunday during the Gospel. In the very last line, Jesus says 'don't tell anybody who I am,' and he says that a couple of times throughout the Gospels. I'm just curious as to why; one would think that he would want [the disciples] to tell people who he was, right?"