Any creative software is full of distractions that give you excuses not to be creative. In presentation design this could be experimenting with fonts, colors, drop shadows, 3D rotations, or checking all those spectacular animation effects.
Creativity requires the opposite. A tool with few features, which you now inside-out, that enable you to jot down/capture your thought somewhere before it is gone. You have an idea how to tell your story, struggle with a PowerPoint feature, spend 15 minutes Googling tutorials, and fail to get back into the creative flow after.
Use a notebook (or my simple presentation design app SlideMagic) to capture your idea from start to finish before it evaporates.