I remember making macaroni & cheese for the first time. I got to the “bring water to a boil” step and was stumped. I asked my mom how to tell when it was boiling. “You’ll see lots of tiny bubbles rising to the top.” I spent the next 5 minutes running back and forth telling her what was happening and asking if that meant it was boiling. When it finally happened I said “Oh! It’s so obvious, I get it now!”