Why do Czechs call Venice Benátky?

Like the names of many foreign cities, Venice’s name has been Czechified – that is, put in a form that more easily rolls off Czech tongues. In the case of Venice, this happened at least as early as the 13th century because that is when a Czech town on the Jizera River was christened Benátky nad Jizerou (Venice on the Jizera), likely because it shared its namesake’s proximity to water. Indeed, the word benátky – which appears to have entered Czech through Slovene – came to mean any swampy place. The allure of Italy must have been high at the time for two other Czech towns bear the Czechified names of Italian cities. Verona inspired Beroun and Brindisi gave its name to Brandýs nad Labem. Other Czech names that presumably went through a similar process include Janov for Genoa and Soluň for Thessaloniki; conversely the Czech Postupim gave birth to Potsdam, and Vratislav to Wrocław.

More interesting are the cases where Czechs actually translate the meaning of the place name so that Munchen becomes Mnichov using the Czech word for monk, Kaliningrad (formerly Königsberg) becomes Královec a translation of könig or king into Czech, Pětikostelí (Five Churches) is Hungarian Pécs, and Sedmihradsko is Transylvania (known as Seven Cities in German)

Many will also have noted that two of the Czechs closest neighbors bear unusual names. Germany is called Německo and Austria Rakousko. The origins of the first are easy to pin down. All Slavic languages use some version of the word “němý” (mute) to refer to Germans. In the old days, it was a way of saying that Germans were a people who spoke an incomprehensible language (as opposed to other Slavs who were presumably more comprehensible). The word Rakousko is harder to track. My internet search reveals speculation that it derives from the castle Raabs (formerly Racouz or Ratgoz) which was the first large fortress that Czechs would encounter in traveling to their southern neighbor.

For longer lists of Czech versions of foreign place names, see the following websites:
http://mmh.cz/sklad/mj.htm
http://www.labo.cz/historickenazvy/

After giving my girlfriend a bunch of flowers, I was told never to give her an even number of flowers again. Why?

It is a Czech tradition that even numbers of flowers are given only at funerals for the deceased. All other bouquets should have an odd number of flowers. Where this tradition comes from is anyone's guess, but since the same rule applies in many European countries, it is likely to have arisen long in the past when numerology still held sway.