Have you noticed that most feature films are about two hours long?  If the world's best directors with the world's best scripts, best actors, and best special effects have decided they can keep peoples' attention for only two hours, what makes you think anyone will pay attention to you for longer?

Accept that two hours is the outer limit for your most important discussions or presentations.  Any meeting that goes longer than two hours needs to be broken into two hour chunks.

Most of the time, you'll need your interactions to be much shorter, packing several different ones into two hour chunks.

What do you think?