Most of the time I get the work done, yes. But there are other times where the client doesn't have realistic goals, like the last project I've been to, they just say something like this:

"We need to ship this on Monday May 11th, so we need you to aggressively plug away on this. You still need to do X and Y. I'm going to put something together with info on how to prioritize the work."

And this after 2 weeks of hiring me, then they say nothing and fire me, without a word, while I'm getting the work done.