Easy to say now, but it was an epic moment. When you see something change the world, and you're standing right there actually working in the discipline where the change occurs (human factors design) and it affects your work immediately in a positive way, you tend to get a little excited. At that moment, the quantum leap from command line interface to GUI was nothing short of earth shattering. (And before you point out the well known fact that Apple didn't invent GUI, I must remind you that they were the first to figure out what to do with it, as xerox had no clue. Thankfully somebody did.)