The Iceberg Secret article: Joel on Software - The Iceberg Secret, Revealed also known as Chapter 25 in the Joel on Software book. Has inspired in me a profound revelation, when it comes to developing software.
Once you understand the Iceberg Secret, it's easy to work with it. Understand that any demos you do in a darkened room with a projector are going to be all about pixels. If you can, build your UI in such a way that unfinished parts look unfinished.
Outside of the context of my life this may not be huge to you. But if you shared some of the experiences I have over the past 5 years, you would understand how profound this is. Or you might say, yeah, I know that, who doesn't know that.
But it doesn't matter, based on the understanding I reached this morning reading Chapter 25, it will forever alter the way I handle the creation of software. Sure there are other great insights provided by Joel, and they may all be even more important, or seem more important. But as for me, as for right now, there is nothing more important to understand.
When it comes to software there is nothing, absolutely nothing more important about it than the user interface.