Hahaha... Not so much the DOF for me, but the character of the lens. Still, I am sure my want is unreasonable to some extent, but then passion tends to do that, much as I hate to admit. Or maybe I am a bit of a gear head. That sounds about right.
I know exactly how you feel. A few years ago I walked into a used camera store and then came out with a Nikkor 50mm f/1.2 lens. I never thought about owning that lens at all until I saw it on the shelf. It was so finely made that I just had to have it, then and there. That was one expensive window shopping trip ($500 or so), but nothing like the Noctilux.