I have a few bow ties - most of them "non-formal" - all self tie. I have only two formal ones. I can't get past the association of a pre-tied tie with a little boys school uniform or "Sunday Best" outfit. Bow ties have been in fashion for the past year and half or so, (was a good excuse to add a couple to the arsenal) although I think they have always been in style. The most curious thing anyone ever said to me about a bow tie came from a co-worker at an old job many years ago. She was from Ireland and she said "it's said that you shouldn't trust a man who wears a 'dickie bow'." She never told me why (or I can't remember.) Interestingly, I only wear a bow tie with a kilt if I'm going formal.