Model Railroad Aphorisms

In talking to clients and trying to help folks on forums, a couple of pithy comments have been springing to mind recently:

It's no fun if the trains don't run.

and

If not drawn to scale, it’s liable to fail.

The first speaks to the importance of reliability in considering design options, the second to the tendency some have for flights of fancy about what can actually fit in a given space.

Hokey? Yeah, I guess. But how many misguided newbie layout design train wrecks (literally and figuratively) might have been avoided with the liberal application of these two ideas?