I recently heard and was extremely moved by the idea that the kitlen worn on Pesach, Yom Kippur, and under the chuppah are intended to resemble tachrichim -- and are, in some cases, the actual garments in which the man will be buried.
It makes some basic and deep sense to me that one wears one's soon-to-be burial garments for such shattering times as Yom Kippur and the chuppah--one's personal Yom Kippur, and the moment at which one's life doubles in meaning. Nothing, it seems, could make the call to seriousness of these occasions more real, and more desperately urgent.*
I was wondering which communities used or still use the actual contemplated burial garment as beged for the chuppah, etc.
We should live to see the days of Moshiach.
* (As for Pesach, @SimchasTorah pointed me to this prepossessingly charming and nimble exploration--possibly from our own @EliezerEisenberg--of the kitl's dual symbolism and its expression in minhag. Still, I can't say I fully see why Pesach rises to the level of the others. Any comments would be welcome.)