Okay, interesting ;)
I wouldnt be so sure If my blood is 100% Polish ;)
Who can be sure of it ? And what does 100% mean ? ^^ LoL Purity means nothing ;)
For my part, my mother comes from Silesia (Gliwice). Her maiden name was Nowak (pretty common in Poland, LoL, actually the most common name). Her mother (so my Polish grandma) maiden name was Kupka (if you speak Polish, you may know what it means...hehe), but when i google it, i find many Czechs "Kupka"...
My father is from Brittany (northwest of France) but as the region has been invaded many times, i may have some Skandi blood as well as English, etc. ;) Who knows, i'd like to have a DNA test someday, but it's pretty expensive...