Tangential at best, but I'm reminded of the opening of Aleksandar Hemon's The Lazarus Project, where he informs us that Bosnian Independence is celebrated on its official February 29 every four years and on random nearby days for the other three.
Back to Milan, it looks like 81 is in his immediate future... unless I am counting incorrectly from April 1, 1929.
Well, happy birthday, Milan Kundera. Stay healthy and keep writing! If the truths or rumors about your informant youth are true, don't sweat it. People have all kinds of blemishes on their official, unofficial, and other dust-strewn records. A bit guilt or shame always beats a significant jail term in this regard. To make amends (if the informed upon is still alive), you could buy the guy a modest but well-crafted automobile; if he has passed on, then buy his descendants some shares of stock along with a long personalized letter. I've heard people do these things.
Indeed, my own motives for blogging could be seen as less than pure. Believe you me, I am counting on all of these people misspelling your name as "Kudera" for them to possibly learn of and purchase this book: http://atticusbooksonline.com/forthcoming-titles/fight-for-your-long-day-by-alex-kudera/ I suspect this occurs in 1000s of blogs and personal pages; yes, Milan, you are the second entry if one googles Kudera without the quote marks. So again, keep writing!