The Light Vs. The Dark
"You can't do that."
"That idea won't work."
"That isn't how we do things."
Shutting down someone's ideas is snuffing the match before it can become a flame.
In a dark room, when a single point of light appears, it draws all attention immediately. It burns the eyes; it sears the synapses. And rather than let their eyes grow used to the light and use it to look around and see what they can see, the fearful shrink back, then scream for you to put that light out. Because it burns. Because it causes discomfort.
Don't let them put your light out. If the people in the room try to snuff your match, move to another room.