The truth is that the name comes from Upper Silesia. This was (and is) a region in which German and Polish influences get mixed.
In our case, also Czech influence can be added - Kurzidims' home county is a melting pot of all three languages.
Nearly all Kurzidim families have ancestors in Leobschütz county, south of Oppeln near the Czech border. My oldest known ancestor was Balthasar Kurzidim from Eiglau (who died in 1743). This village ist the historic center of the Kurzidim families, even the oldest non-destroyed church record (1688) reports about several families whose name was Kurzidim. In Bauerwitz, the nearest town, two Kurzidim families worked as shoemakers from at least 1750 to 1841.
The oldest Kurzidim I know of was Caspar Kurzidim, who was registered to pay taxes in 1531 in Bauerwitz. Unfortunately I can't check if he was my relative.
The name exists in Germany and Poland in 8 varieties: Kurzidim, Kurzidym, Kurzydym, Kurzydem, Kursidim, Kurzidem, Kuřidym and Kurczydim. This list mostly complies with the varieties in centuries of church records. Of these varieties, 'Kurzidim' is the most widespread, as it also was in old documents.
The website verwandt.de showed a map of Kurzidims' home counties in Germany (about 220 people) and Poland (about 160 people). The Polish map shows that some of us are still loyal inhabitants of our traditional country.
This map contains Kurzidims' villages in Upper Silesia: