Zee nose blowiiiing

Apparently I found an explanation on the nose blowing phenomenon affecting the Czech people:

"This is an odd one, but in the usa, sniffling due to a cold or breathing trouble is no big deal, whereas public nose blowing is rather frowned upon. in czech it is the opposite. sniffling is considered extremely bad manners, whereas people might blow their nose mid sentence. carry tissues at all times"

Now that's enlightening :)
For the more interested in Czech etiquette, click here.