We, Bulgarians, usually identify ourselves as such with the "I am a Bulgarian Youth" poem by Ivan Vazov. Later on, unless you go on to become a member of a nationalist party, you don't feel any particular need to remind yourself of "I am a Bulgarian." Such a statement, despite its straightforwardness, could invoke a measure of uncertainty, like the invisible steps on the front cover of this book. It is not because you could be something else than a Bulgarian, but because the affirmation presupposes a previous agreement between yourself and your compatriots about what it is that makes you Bulgarian and what makes Bulgarians a community.
This is a difficult task that quickly entangles you in bookish definitions that will likely obfuscate rather than illuminate the issue of who you are.