So you're a clever clogs. You sit in meeting's stir things up, make people think, get them excited over all sorts of stuff. But somehow the strategy that get's signed off, and the resulting work is never what you had in mind. How come? if people were that interested, why did we revert to type?
Here's why. People like to get exited about stuff, but when it come to actually doing it, it suddenly becomes risky, so they revert to type. You need to keep the momentum going. The more it builds up a head of steam, the more 'real' it becomes the more it's going to happen.
So keep that initiative. Next time you get people interested in something, get an agreement to make something, or do something. That might be some desk research to share for next time, an agreement to do a workshop to develop stuff together (make the stimulus amazing), could be proposition boards if you have some sort of direction to explore -anything. But get an agreement to make something or do something for next time, don't let it fizzle out, don't let doubt creep in, don't let the easy option in.
In the end of a day, we work in a factory, it may be an ideas factory, but it's a factory nevertheless, so keep that production line going, keep working to go beyond talking - to making or doing stuff.
In other words, always be closing