My YDNA Cousins

I've taken all three kinds of DNA tests for genealogy (i.e, for the paternal branch, for the maternal branch, and for every branch of the family tree). For all three, I've been in contact with distant cousins, but for nearly all of those distant cousins we will never know exactly how we are related. Still, it is interesting to see the ancestral locations and imagine how those connections came to be.
For the paternal branch, YDNA, there are a variety of entry level tests, and then there are a variety of upgrade packages. About a year ago I upgraded to a super-deluxe YDNA level, a level which qualified my results to be analyzed at ytree.net. But since mine had already been analyzed at the Family Tree DNA U-152 site, it was only recently that I provided my results for additional analysis at the other site. Both sites agree with my position on the tree.
The ytree.net site has an interesting feature in that the ancestral locations can literally be seen, since individuals on the tree are displayed with a flag indicating their known ancestral nationality. For example, this small portion of the tree at ytree.net is the DF90 branch, which includes my result, which is displayed with a Hungarian flag, for my grandfather.
Considering both sites, there are a handful of results that are closest to my own, with one of them appearing only on the ytree.net site. That result is displayed there with what was initially an unfamiliar flag. From the Family Tree DNA U-152 site I already knew that the DF90 results available so far are widely dispersed across Europe, extending to Turkey and Algeria. Seeing the unfamiliar flag, I initially supposed that the flag must be for a country in Europe, or possibly adjacent Mediterranean neighborhoods of Africa or Asia. Eventually I realized that it is the flag of Barbados (which happens to be celebrating this year its 50th year of independence). While coming to this realization, I had started to read The Immortal Irishman by Timothy Egan. Egan notes, in reviewing the history of Ireland, that starting with Cromwell, and on later occasions, survivors of British punitive incursions were sent as slaves to Barbados. Although there may be other explanations, I think that the DF90 connection to Barbados is via the British Isles, either through a white slave, or possibly through a slavemaster. That would be consistent with a couple of other results close to mine, from Ireland and from Scotland.
The Barbados result is from the 1000 Genomes Project. All of that project's Barbados samples are labeled African Caribbean. It's conceivable that the Barbados DF90 connection to Europe could be via some Old World route between sub-Saharan Africa and the Mediterranean area. But I think that scenario is less likely than the British-Isles-to-Caribbean connection. I've been in contact with DF90 cousins who have roots in France and in Turkey, but it looks like the British/Caribbean connections are even closer. How my Hungarian grandfather fits is a mystery. Did he have a paternal ancestor in prehistoric times who was among a small number of Celts left behind in the Carpathian basin when their kin migrated west? Or was his paternal ancestor recruited from western Europe during the Middle Ages to fill a population void in Hungary? It will be interesting to see what details may be revealed as more people upgrade their YDNA tests.