You may think i am a cynic but here is the harsh truth: people lie. Everyone is a liar and tries to say what they really mean under false covers and words. One of the prime examples of such lying is that which is done by your boss. He may come to you and say that he wants you to be ‘concise’ in your presentations. Beware- he very well may be lying to you!
When someone says to you that they would like you to shorten or summarize your presentation, they really mean to say something else. If people feel that you are droning on and on and they are getting nothing useful out of your speaking, then they will want you to stop sooner than later and hence ask you to be concise the next time you speak.
That is why people come up to me and ask me to help them become a concise speaker. But that should not be the goal. The goal should be to become an interesting speaker that can keep the attention of the audience inside his or her fist for however long he or she pleases to. The goal should be for you to learn how to have people understand your ideas and remember them so they can take action.
People are unable to watch uninteresting videos even if they are only 5 minutes long but are willing to sit through a 3 hour long movie that is far more interesting. Or think of it this way, people may end up forgetting small, 5 minute reports given by boring, unknown speakers but they will line up for blocks to see Anthony Robin speak for 12 or more hours in a day.
So it is not about being concise. It is about being an interesting and better speaker. In order to start doing that you must begin to infer what people are saying to you because they will lie sometimes.