All presenters have to answer a simple question that lurks in the back of the mind of each member of the audience:
What's in it for me?
Note the challenging nature of that question. The listener is not asking:
What's in it for other audience members?
What's of interest to the presenter?
What's in the interest of the greater good of the community?
Ah, no. Each member of the audience walks in with one benchmark. Now there are many generous and wise souls who will be flexible on the issue. They'll recognize that although they may know more about time management than the average bear, other audience members may not and so if the presenter takes some time to describe some time management techniques, these members won't take offense. They'll be patient.
Up to a point.
That's why pacing can be so important. Presenters who are dealing with broad topics have to move things along with the dexterity of a late night comedian tossing out punch lines. The comic who tells a long, drawn-out story is a portrait in courage or foolishness because if that saga bombs, they bomb. On the other hand, if they pepper the audience with a variety of one-liners, the ones that don't work will be hidden among those that do.
Presenters juggle a similar concern when addressing a variety of subjects. Moving quickly helps maintain interest and so too does the ability to pour new wine in old bottles. The fact that some audience members may have heard a lot about time management does not mean that they'll be resistant to hearing a fresh perspective.
I recommend to my classes on presentation skills that they consider the possible objections of most skeptical member of the audience when preparing their material but do not permit such individuals to ruin the mood when presenting their materials.
"What's in it for me?" is important and yet, as with all things in life, it has reasonable limitations.