We have a client who is like this. It's intolerable, but also so predictable that we basically deal with it by just weaponizing it. We know that when we present information to him, we simply work towards building a message that he will take as his own eventually. Initially he'll crap all over the idea, but invariably will return a few weeks later with a "great idea" that will just be what we told him and then we'll basically get to do whatever we wanted to in the first place.

It requires some ego squelching but in the end we accomplish what we want and everybody ends up relatively happy. However, even after years of successes, this particular client still treats us like the hired help (which I suppose we are).