Why do married women hang on to their wedding dress and do husbands hang on to their garb?

I think most women are more sentimental than most men, and the wedding day represents a major change in their lives. Also, we (women) put a lot of thought and effort into finding our perfect dress for that day and some also lay out a lot of money for theirs. Like another answer already said, men often rent their tuxes, and aren't likely to be as sentimental about what they wear (wore) or put a lot of time and effort into it.