I know the wearing of kilts fascinates the rest of the world, but why in the world do Scotsmen wear them?
Well, actually, they don't wear them nearly as often as you might think! Big party occasions like weddings and New Year, traditional events like Highland games, pipe band marches, or formal events where other people might wear evening dress, are the times you're most likely to see them in any quantities
They've become a symbol of "Scottishness", of patriotism, but it might surprise you to know that the original kilt looked very little like the Highland dress of today! Today's kilts, grew out of a romanticized version of what was basically poor Highland peasant costume, and Sir Walter Scott generally gets the credit for "inventing" it!
Basically, a resurgence of Scottish pride. The Jacobite Rebellion had somewhat unfairly tarred the entire Scottish nation with the same brush of disloyalty and rebellion. Highland culture, in terms of language and dress, was outlawed, and it was very hard for Scots to thrive in this general atmosphere of mistrust. Victoria, however, fell in love with the Highlands, and with Sir Walter Scott's romantic view of Scottish history. At least partly as a result, the Scots as a whole adopted Highland symbols like the kilt, to represent their own patriotism, their newly rediscovered pride in their own nation.
And if nothing else, you have to agree that they're fun :).