I'm currently nearing the end of David Marquet's "Turn The Ship Around" [1]. The author talks about this same point in his book. One of the points he makes is that different people will get the message at different stages. So repeating it and being consistent are important. As far as I remember, Simon Sinek goes through the same idea in his "Start With Why".

By the way, "Turn the Ship Around" is a great book, and pretty easy to read.

[1] http://www.davidmarquet.com/