It changed over time. In primary school I was taught animal, plant and fungi kingdoms, with protists and bacteria being outsiders and not classified in any particularway. In high school it was three domains of archaea, bacteria and eucaryotes and eucaryotes contained the three kingdoms of animals, plants and fungi, with allusions made toward the fact that fungi and animals were somewhat closely related. Protists were understood to be a varied group.

That said the messiness of not being a kingdom makes protists more interesting rather than less to me.