1. You say “opa” instead of sorry when you mess up.
You just bumped into a stranger, stepped on their foot and nearly crushed it by accident. Opa! You opened a bottle of champagne and its cork hit your best friend’s forehead. Opa! You burnt your dinner in the oven and had to put out the fire in the kitchen. Opa! It may not exist in the dictionary but “opa” is so much easier and faster to say than the long complicated Bulgarian word for “sorry” (Съжалявам).