Same. All through school and in University, lecturers and professors called it G.U.I., then when I entered the workforce, managers were saying "gooey", I was so confused, I didn't know what they meant and I couldn't take them seriously when they said it.

Now 15 years later, I still cringe when people say "gooey", I deliberately make an effort to say "G.U.I." in an effort to correct them.