Very odd comments. Obviously you know nothing about the country and people.
The important difference between Bulgarians and nations like Poland and Czech Republic is that we are not slavs. We are more similar to Serbians and Hungarians even to Russians and Ukraine (actually they are similar to us, because we are older nation). The similarity between so called slavs and Bulgarian kingdom is that you were our neighbors long time ago and you were spoken similar to our language, based on our alphabet (glagolitic) on that time. Some of “slav” tribes became part of Bulgarian kingdom. So yes, we were mixed a little but not as much as you think.