Heh, I was the same way, kind of. I only knew how to tie a half-Windsor and never really figured I'd need or want to know how to tie a full Windsor, Pratt, or a Four-in-Hand. But that versatility can make a big difference in style and proportion (there it is again!), depending on the tie material, collar, pattern, and style you're looking for on any given occasion. It adds another dimension to spice up your dressing style. The Four-in-Hand has an off-centered look to it which I used to dislike. I use it for a more casual or 'haphazard' look.

http://www.tie-a-tie.net/