I just saw this one and thought that it nails it.
Don't underestimate me
I know more than I say.
Think more than I speak.
and
Notice more than you realize.
I've always said to my kids, when they aren't sure what to say because they don't want to seem like they don't know what is going on, so many times they say nothing.
I remind them at that point, they should say nothing, or very little, but continue to listen and watch what overs say or do.
Sometimes, ok most of the time, you learn more by watching or listening then people realize. There are times that you learn more than others wanted you to just by being silent.
But being silent, doesn't mean you don't know some or all of what is going on, and THAT scares them more than anyone will admit.